I agree with this complaint. I recently expressed this concern on the discord a few weeks ago. Other patrons argued that one has to take "failing" a quest in a wider sense of failure. But let's be honest: the NTR is often a choice made by the player, not about failing a quest. Sometimes the NTR really is about losing a fight or failing a quest. But there are plenty of cases where it is a choice, as you expressed. This is contrary to Chyos's explicit statement on the About section of his Patreon page regarding the place of NTR in his game.
However, in the particulars you addressed, I'm not sure I agree with you 100%, and certainly not in some of the ways you think it ought to be changed. I won't get into the particulars, but just wanted to note I am not agreeing with you on every point, just your more general point.
It is probably worth noting that there is a big NTR crowd among the patrons, and no doubt Chyos likely feels some pressure to provide the NTR. He forces a balance on suggestions so that there is always a non-NTR option as well, which is good. But it doesn't go far enough, since there also needs to be a way to ensure the NTR is also a matter of losing or failing at something. I don't see him requiring this condition when people make NTR suggestions on the discord.
Finally, one more thing worth pointing out is that NTR has two senses, one in the narrow sense of netorare, the other in the broader sense of including netorare, netorase, and netori. Technically, when the MC chooses to let Kate be whored out, that is netorase, not netorare. I take Chyos' statement on NTR to be about netorare only, so choosing to whore Kate (tavern) or Tia (orcs) could be argued as not being NTR in the relevant sense, because it is not netorare, although it is netorase.