I won't comment on whether this applies to Kai because, as you pointed out, we don't know Kai. But what I will say is that the "morality issue" (which I don't actually think it is, Ben does, I think it is an image issue) comes up with Kai for a couple of reasons. First is the fact that he has gone from stripper to pro BBer very successfully. This gets some people offside due to that morality issue, I personally don't care. Secondly is the G4P video. This one is a different kettle of fish because of the fetish nature of the video. What gets me about this sort of thing is the impact it has on the sport. BBing is already regarded by most as a freak-show and weird, if a champion pro BBer and possible Mr O is doing fetish videos then it just confirms mainstream opinions and further drives BBing out of gyms (that we have popularised), further out of the media, and makes us a laughing stock.
We become further marginalised because of the actions of someone in the industry being held to represent the industry. Tiger Woods didn't bring golf into disrepute, he brought himself into disrepute. Unfortunately BBing doesn't have the profile golf does, so BBing is tarred with the same brush as Kai. Is it wrong for Kai to make a fetish video; no. Does that video reflect poorly on the sport of BBing; yes. Yes because it just compounds the sordid underbelly of the sport and shines a spotlight on it for the mainstream to further malign BBing (The same can be said for drug use). But why sordid if this isn't a morality issue? Well simply put you are associating BBing with fetishism, with the fringe of society, and not with the sport of BBing. This makes BBing supposedly less accessible as you are the fringe of the fringe, this makes BBing marginalised from acceptability.