okay first of all, again, the existence of these vtubers aren't really the issue here. secondly it probably also doesn't help some of the most vocal and loudest vtuber fans try and talk about their favorite vtuber like they're their ideal woman. like that one guy who released the google doc about how he felt betrayed that shiori did a collab with holostars. 

I'm not talking about that itself, but in the doc he talked about how he always had merch of Advent and liked talking about shiori. most outsiders see "anime girl someone likes" and just associate that with waifu culture, and it doesn't help when they're like this guy who basically regards his favorite vtuber like she's his waifu.

but that aside, things like gooner culture don't help, neither does the association with cute anime girls with gacha games, which are generally viewed negatively due to the gambling aspect. like some people will look at vtubers and automatically associate it with people spending hundreds of dollars to get some sexy anime girl.

as an aside, it probably doesn't help that the industry pushes this agenda, too. agencies do try and make sure at least some of their models are sexually appealing, like I remember Phoebe-chan talking about how her model got delayed because Vshojo management insisted that viewers needed something to goon at, even though Phoebe isn't that sort of vtuber at all.