I always give last names, even to minor characters because if I didn't, even I would get confused lol
I finally charted out a family tree (for a really big, extended family) a few weeks ago and half of them still don’t have last names 
but most of them barely even show up side characters, so it’s all good. At least they have names and I’m clear on how they’re all related 
I always give last names unless I can't for plot reasons. For example, Shilo has no known last name because even he doesn't know where he came from or his own mother's last name (it's actually Castello but my readers don't need to know that )
But yeah all my other characters have last names. Sanborne, Clovehart, Gallo, Swift, Arena, LaRou, just to name a few. My favorite is actually Martin's last name, Gale. Because it alludes to a type of training collar called a martingale
See that makes total sense to me— your character doesn't have a last name because it's a plot element! If it's too much for me to come up with a specific last name, that's when I throw in "Smith" or "Johnson" or whatever else common last name for their ethnicity etc. 
As someone with an "unusual" name myself, I'm bored of always seeing the same ones in fiction. Especially given that mine isn't actually unusual or foreign to English speakers, it just takes more digging on a baby names list to find.
While the advice is also pointed towards a western audience, well, I do live in a western country and there's one person out of the 20 I work with that is a Jack, Paul. John. I think it's pretty outdated. To echo Diego, a more realistic approach is pulling from multiple countries/ cultures who have their own Jacks, Johns and Marys.
Yeah, I thought about that but I didn't wanna have to say "pit lick" each time, so yeah. "Pet lick" was a close second though!
Oh my god don't get me started on names. My first name is already a bit unusual where I live and it's constantly misspelled. And seeing a work with only 'normal western' names like Jason, Samantha etc. makes me roll my eyes so bad.
No, I don't mind this at all. Even names unusual for certain can have a history explaining why character has such a name and be a part of understanding that character.
Also some names have different variants in different languages, like Andrew has same roots as Андрей or Andreas - all come from greek word meaning "man". I saw examples in Russian modern literature where Андрей would be called Andy and it signified that character is western-leaning type of person and trying to look cool and different from people around.
On topic of just unusual (like fantasy) names I don't mind that too, but I'd say there is a hard to explain difference in quality of those. Some names can be a tongue twisters but still stick and be memorable, others seem simple, but fall out of memory with ease. I think that is less problem of "unusuality" of name but rather if name fits the character.
I don't want the names so confusing and long I can't comprehend them, but I prefer a slightly unusaul name. Boring names are also fine if it matches the character. You do have to think about the personalities of the character's parents--what would they have named them as? It's not just about marketing, it's a huge story building tool. But if all the names are the same and boring I forget who's who.
That reminds me of my other rule: I don't share names lol
If someone is named "Jim" his name is Jim, and no one else in the entire story - or in my writings EVER is named Jim. Generally.
I do have a red-head named Will 
but he's from a super old version of a story involving Hito that just... isn't a thing anymore. And he was so minor. I don't even think of him as a character named "Will" anymore.
I do give pretty much everyone last names that are required to have them. (Older or special characters do not have last names if it's not part of their culture. ie Neo Phyte I mentioned before - Phyte isn't his last name. It's just the truncated name people call him as, unless you're his beau (or best friend) and then you can call him Neo.) But he introduces himself to people as "hi my name's Phyte".
I mean if I’m being honest, then I don’t really mind. I like adding uncommon and rare names in modern setting stories and doing the same to fantasy. I’ll have some people with names like Atlas, Wayra, Calder, and Oracle in one story but also have much more common names like Charlotte, Nicolo, and William in that same story.
It really depends on the person. Not so much the story type.
I think a lot of it depends on the tone of the story. If it's a more lighthearted story and doesn't take itself very seriously, I don't mind unusual names. If the story wants me to take it seriously, unusual names can be annoying.
This applies to all genres. High Fantasy that's really self-serious and has ridiculous names with a bunch of apostrophes and stuff is really annoying. Fantasy that's goofy and knows it's goofy having ridiculous names is just part of the fun.
It's all about what's tonally appropriate.
Personally not really, but I think it's entirely dependent on the story and tone. I'm much more liable to swallow a weird made up fantasy name like... I don't Ronmark or something in a high fantasy or sci-fi than I am a realistic drama.
Depends on the context of the name. The most important thing is consistency. And I don't mean consistency in using unusual names. I mean consistency in the types of names so they can be imagined to have a similar etymology unless you have a VERY good reason for it. Like the story takes place in NYC or a character is clearly identified as a foreigner. If the story takes place in some random place in america you won't see a bunch of korean names most likely. And immigrants typically name their children in names more traditional of the country the child will be growing up in. Conformity is a powerful force in society. You want the place that you're creating to feel grounded and real. You can usually tell when you have a western anime fan trying to write something that takes place in Japan. The names are mostly nonsensical and just sound vaguely japanese more than show any understanding of the naming conventions of the country.
That's still not very realistic, honestly. There's immigrants, there's parents who really like a certain culture, there's people who don't actually look up traditional names(or use alternate spelliongs) and just go for whoever is currently famous on TV. Even in Brazil where we latinize a ton of terms, I still have plenty of acquaintances with unusual or foreign names.
I do get your point though, you can't have everyone in your Canada setting have japanese names or people question if you just didn't know how to write another location. But a handful in the middle that are foreign and they're still native to the city/country isn't too bad!
Just to be super clear, this isn't my advice, it's just something I keep seeing on a lot of how to create character advice articles and videos and I wanted to see if it was a real thing these days or outdated but still parroted like that "said is dead" advice.
Yeah, this is sorta a sign of a beginner writer in my mind. They should be situation appropriate.
I think it's mostly directed at western audiences because most the people giving advice are English speaking and assuming you're writing for an English speaking audience. As I mentioned above, it's the Japanese equivalent would be giving everyone common Japanese names. I don't think it's supposed to be anything about immigrants or foreign names so much as if you've got a group of girls rather than calling them Duchess, Alison, Cassandra and Minerva use more common standard names like Sarah, Anne, Rachel and Mary.
