The only justification I can see for banning a game that people claim toes the line but doesn't definitively cross it (which I think we can all agree on, if Senran Kagura did clearly cross a line it'd be banned already), is because the members it attracts to this forum and the greater impact those people have on the rest of the site is overall a negative one.
So let's get some hard examples of the kind of stuff the makes up these games, shall we?
Obviously these two clips aren't "the game" in that they're side activities or whatever, but I don't think that matters. If you play these games as a means of sexual stimulation and can admit as much, while also admitting they're problematic for a plethora of reasons... congratulations. Anyone who watches and enjoys porn is more or less in the same boat.
However, I take issue with people who can play a game like this, engage in activities like the above clips and even the main games themselves and not come away with some admission that these games are pretty gross. These girls are put in positions of weakness with red cheeks and tears in their eyes while their clothes get removed or blown/shot off. There are mini-games where you can grope them, lift up their skirts, shoot water at them, slap their genitals while they shake you off and say things like "Hey, your eyes are scary". I think anyone who engages with that sort of thing and doesn't understand how potentially harmful it is and then gets defensive or dismissive when people take issue with it, are not people that should be welcome in this forum. This is all of course ignoring for a moment the issue of the age of these characters, which I don't know enough about to feel comfortable making any definitive statement on. The sort of stuff in the above clips is already gross with the assumption the girls are supposed to be over 18, it only gets worse if they're younger.
I would appreciate some candid responses from the people who are so defensive of these games. Why do you enjoy being pandered to in such a gratuitous, over-the-top manner? Is it the simple interactivity and the illusion of intimacy that the medium of video games is able to provide when compared to... say... porn? What do you get from discussing this kind of game with other people? Finally, and perhaps most importantly, why do you feel the need to defend it when it is so clearly ludicrous and harmful in SO many ways?