I'm not enough of a masochist to waste my time on a shitty teen romance. It's one thing to be a skilled writer but another to actually write something good. A story where all of the characters are shitty and no one is worth rooting for is a shit story, regardless of how good the writing is. Plain and simple, the story is trash because the characters are trash.
I watched Gokudo and only barely managed to enjoy it thanks to how trashy the protagonist is. Fortunately, the other characters were good and the writing itself was good enough to just barely overcome the trash protagonist.
Making any character unpleasant is going to up the difficulty for making something people will actually spend their time on. Even making the big bad a trash existence is a risk of alienating the audience. You have to both be a talented writer and carefully craft your story to overcome the obstacle created by including any character people find unpleasant and/or unrelatable. Even a good protagonist that is unrelatable can greatly up the difficulty of crafting a story people will read.
The fact is, the author raised the bar way too high by having the entire cast be unpleasant, if not unrelatable, to all or most of the potential audience. Personally, I don't find the characters relatable at all. So, I have zero motivation to get past how unpleasant they are. The story isn't even unique enough to motivate me. Honestly, this is a straight up failure on the author's ability to get the audience drawn in to the story. It obviously worked for a tiny niche but left the rest of us not wanting our time wasted.