So, as expected, this ending is stirring up a hornets nest of criticism and rebukes of the way the story ends and I've got a lot of mixed feelings on it myself. On the one hand, I praise anyone who wants to tell a different kind of story and doesn't let anyone pressure them into changing their vision so congrats to Sumo on that, however, I can see how there are aspects of the ending that are disappointing given the events that preceded it, and I'm not just talking about Nikki.
Unlike others, I accepted that Taylor and Nikki woudn't end up together but throughout the story there did seem to be pretty clear breadcrumbs sprinkled about that indicated Nikki may have developed deeper feelings; like when she almost said "I love you" when they had sex the first time, or how she avoided telling him how she really felt on multiple occasions that even Taylor could tell she was hiding something, or even the fact that she initiated their sexual relationship which could be seen as just being promiscuous and open-minded but could also be seen as her seducing him in order to make him fall for her. At the very least I thought we might have had an unrequited love thing with Nikki admitting to having feelings for Taylor but he doesn't reciprocate, which would've been totally fine, but having them both admit to feeling absolutely nothing doesn't feel right given what's come before. Even some of the dialogue in that scene where they're hashing things out (if you've broken up with Molly) seems to suggest that Taylor wants something more with Nikki.
As for the Molly-sext-breakup part, it just felt like a really cheap way of getting Molly out of the picture for the "bad ending". For one thing, Taylor never bothers to check his phone afterwards to see who was it that sexted him which you think would be the first thing he did, but more importantly, no girl in this entire game has ever sexted him before so why exactly would they be doing it now? It's been months since he had contact with Corey or Skylar so it couldn't be either of them (I also don't think he ever got Skylar's number as they only ever met randomly), which just leaves Chelsea and Jessica as people who Taylor can have sex with within those 3 months after Ashley gets carted off to jail but, again, why would either of them sext him? It just doesn't seem to fit at all within this story except as an easy way to get rid of Molly and make you feel like shit for sleeping around.
Finally, I get how many of the girls that Taylor can and does hook-up with aren't exactly considered viable relationships given that he's not as close with them as he is with Molly and Nikki, but if the whole point of his journey and his sexual exploits with Nikki was to give him confidence and to help him get girls, why is that if you break up with Molly his life seems to go down the tubes? Why can't you end up having a relationship with another girl just because you fucked things up with Molly? Sure, he's still in college with his whole life ahead of him and good things could still happen, but having it end with him not getting any of the girls even for a short-term relationship seems like it's the antithesis of this story's purpose, unless the moral of the story is that you can have all the confidence in the world but don't fuck around indiscriminately.
Overall I feel like the ending doesn't quite match the build up, not because Taylor doesn't end up with Nikki, but because a lot of storylines, characters, and character development just kinda gets tossed by the wayside and certain things seem like they're done for expendiency rather than providing a properly satisfying conclusion.