There are plenty of games out there that have it, why not go play them. I mean I think you can probably get some enjoyment out of this even without NTR, though I am not a fan of NTR so my opinion probably won't matter much. However, the dev stated no NTR, so don't really see the point posting about it. Dev stated there is none (probably to avoid ppl asking about it) so it is what it is.
And the dev could get $600 from one person to add it but then they might alienate some of their other supporters.