They don't *mean* self-insert, but IME there is a correlation. If you want to feel like you are in the story instead of just observing the story then having some amount of control tends to follow. I'm sure there are KN-type games that are aimed at self-insert folks, but I haven't seen many. Typically the people screaming for choices are also the ones that are furious if you cannot rename the protagonist.
I have never felt that way. Some games I like such as Pale Carnations or Good Girl Gone Bad would just be worse games if they followed the KN format. A KN format alone does not make a game any less of a self insert game. And with the harem themes and its anime-ish tropes I personally think that this game is more of a wish fulfillment self insert fantasy than either PC or GGGB.
That's not to say that wish fulfillment type games are bad - it all depends on the execution and games like Eternum and Desert Stalker (which I think also appeal to the self insert audience) are among my favorite adult games. And I like this game because it is well executed too in terms of the overall story and writing. But when it comes to self inserting, I just think that if you liked to self insert it would be far more appealing to try and do that in a harem game like this one as opposed to something like pale carnations where 3 of the love interests are whores or good girl gone bad where you play as a woman desperately trying to become the biggest slut imaginable.
When it comes to trying to get people to self insert, I think the contents of the game play a much larger role than things like player choices. And this is also why I think that so many harem manga, light novels, korean pornhwas, chinese Xianxia/Wuxia novels etc that I have read try to appeal to readers who like to self insert despite the fact that they obviously have fixed stories because of the medium they are in.
But maybe I only feel this way because I dont try to self insert.