First let me preface this as saying I did really enjoy the vast majority of the game, but like others I do think the potential ending(s) is where it fell a little flat for me.
I like the idea of the happy Molly ending, and having a bad ending of forever alone, but I just feel like there should have been more. I know what the dev has said, but like others have said it doesn't actually matter what the dev says in a forum post, it matters what is written in the story. That is what the users will use to determine how they feel about any characters and endings involving those characters.
A couple things could have easily added more to it, one being with Mrs. S. Frankly if you are not with Molly and you get Mrs. S preggo (which I think happens no matter what right?) then you should have a choice to be with her, or something like that. Hell if you really wanted to appease the incest crowd then you could have thrown mom in for a threesome at some point in the epilogue. I mean he talks about his moms ass and then she flashes him and is wearing more revealing clothes, which all amkes you think something could happen. The other girls I actually get not really turning into longtime companions, although I think we could have maybe got another scene or two with them, specifically Cory, which would have been easy to write the growing apart due to the volleyball and olympic training etc, but I still see them drifting apart.
Now the real issue most are having is with regards to Nikki. With the way it is written, I do believe that having a straight brother sister together forever situation wouldn't happen. But if you are with Molly and you do everything right, Nikki is there together with you and Molly. Molly seems to be very accepting of it and I feel like there are hints of more fun time with all of them. So I have to admit I was very let down that there was no option to continue to have Nikki not just in yours and Molly's life but active in their sexual life. They (Tales and Nikki) obviously love each other, even more than just normal siblings, but not enough to admit they want to change their names and get married etc. I really feel that even if everything else was the same, if all you did was add a way to get the MollyxNikkixTales ending (I know that I tried many different choices attempting to get that option before finding out that it was not possible), you would not have anywhere near the kick back you are receiving. And the reason for that is how it is written, people would not jump to that conclusion without it being written that way. It's pretty obvious that Nikki would continue their fun if she really had the option without hurting Tales and Molly, and depending on your choices Tales does question if they could be more, so it is not like he is completely against it, at least the physical part.
And no I am not asking Sumo to change the end or anything. I honestly hope that he can take the bits of well worded criticism (not the bashing shit, that is not needed or helpful) and use it to better his writing in the future. Like I said at the start, I did really enjoy the game, it was both sexy and funny and well written for the most part. Just try to remember that the reaction is because people felt that there should have been more ending options considering the writing leading up to it. That really is more a testament to the quality of your writing leading up to the end.
And no matter what anyone else says, congrats on the finishing of the game, that alone is more than the vast majority do.