It saddens me to see that this many associate the label with the comic following a boring formula, or assume it will be rapey wish-fulfillment. What saddens me more is that the people saying this do have a rational reason to do so: A lot of yaoi, shounen-ai and BL marked comics (both proffessionally published in japan and webcomic ones) work like this.
Here's an input coming from someone who tries to create something beyond just the above, but still puts the BL label in the thumbnail. For me, the BL label works partly as an advertiser, and partly as a warning. The later thing is neccessary, because this is not just the wishfulfillment of some 16 year old for me - it's the only way for me to express my sexuality and romanticism (if that is even a useable word for it) as a gay transguy who has to wait until AT LEAST late winter 2016 until I can get on hormones. It's important to me, and while I am very open about my sexuality and gender identity and proud of what I am, I just don't wanna deal with a big bunch of straight, closeminded men flushing to my comic and then getting disappointed and whining I should've put a warning on it. I have a follower on another site who categorizes all the female characters of my other comic by their boob size and makes rape jokes on my BL comic and I don't want any more of those kinda people. Putting "BL" in the thumbnail seems to help keep them the fuck outta my business. Although I might put "LGBTQIA" on Bloodroot's thumbnail someday instead, since it has lesbians as well and will have a transgender person... plus some stuff crossing gender lines.
I do have sexual content in my comic. It bothers me that people think that is fetishizing, because it's an opinion built upon the view society currently has on sex - something I want to work against. I don't think sex closes out the possibility of writing a good story. Boylove today, I feel, either shoves sex into the closet like it's a bad ugly sheep, or it fetishizes it to no end and the characters aren't given a chance to become proper... well. Characters!
I want to contribute to a sex positive society, that understands the importance of CONSENT. Is that really so bad?
I also use the label because I am more likely to read BL comics myself. I'm also fairly likely to just stop reading after like 5 pages due to shitty art or shitty writing (although sometimes I keep reading because it falls into the so bad it's funny category). I occasionally read hetero comics or lesbian ones as well (the latter one is far too rare! We need more cute lesbians!) but for the former I really need to be in a good mood and it needs to be very comedic... Otherwise I just can't deal, cause it reminds me of when I was struggling so hard to be a hetero girl myself. Various people have various reasons for looking for one type of romance rather than the other, and I want to make it easier for people who prefer or are willing to read BL to find my comic.