I don't think that 90% of all devs are bad... at lest not code wise.
Where they suck is advertisement and community management.
I say they 90% of them suck for very specific reasons. They all:
1. Give the MC a huge dick and have that be his defining attribute.
2. Make every other sex scene a blowjob, handjob, footjob or titwank.
3. Turn every story into a shitty maledom or harem that wastes our time.
4. Whenever they do a female protagonist, they just can't resist letting you know what the men around her are thinking. (Whoa, look at those tits!)
As for them being bad at advertisement and community management... I dunno, that sounds like a Patreon problem. As long as the devs aren't soliciting themselves too much in the actual game (which a lot of them do). I don't see why anyone would care about how they advertise.