I personally really like getting comments! And I see constructive criticism as a way to help someone improve. I haven't received that much of it really, but one very helpful comment I got on my comic was that the font size was really small and made it hard to read on mobile. So I made it bigger, and that was better for everyone
But that's a very small thing to criticise though (I wouldn't even call it a critique, more of a request/advice). I think for many it's harder to get criticised for things like character design, story, plot, how your drawings could improve, etc. Some can get very defensive about it, and that's why I'm hesitant about leaving that kind of critique on people's work unless they've asked for it. I think people forget that you don't have to listen to all critique - you can just read it, think about it, and then not make any changes whatsoever if you don't agree with it.
I think your way of doing it - asking questions - is a very smart way to give critique though, because you make the creator take a better look at their own work. If I as a creator know in my head that character A is supposed to be in front of character B, I might take it for granted that others understand and see this too. But my drawings might not make it clear enough, and readers can't read my mind So yeah, I think critiquing through questions is a good method.
I think differently coloured eyes counts as a trope, but then again practically everything is a trope :/ And tropes aren't necessarily bad, they're just story tools, and the job is to handle them right.
The comment that purrlpankras received was weird though:
"different coloured eyes trope trope tropes"
That's not really...helpful? I don't know, to me that's bizarre at best, and though maybe hate is a strong word, I find it hard to believe that the one who posted it meant anything positive or helpful with it, because it's just weird. But it could be that they were trying to be funny and didn't mean any harm. I honestly don't know :/ Again, just pointing out that something is a trope is like pointing out that your story has a plot and characters without adding any further thoughts on it.