Lmao. For me, it's if SasuSaku happens in canon. Seriously, that couple is so outlandishly terrible, asspulled beyond words, and so forced/amazingly out of character I will never be able to follow the manga/anime and seeing the NS/SS interactions without facepalming and seething with anger over how Kishimoto could go so wrong. Watching it will be a struggle that I cannot even describe.
As for NaruHina, yeah I will be incredibly angry and criticize it endlessly over how wrong Kishi did things but I don't think I'll necessarily quit the series. NaruHina's a bad pairing and definitely an asspull, but at least Naruto and Hinata were friends. They don't have as much damage and don't bring the large amount of disbelief that SasuSaku would bring if it became canon. It doesn't change the fact that it'll be bad writing, but it's at least not worth quitting for.
I love the Naruto series more than I hate NaruHina. However, I despise SasuSaku more than I love the series.
But I hate to say it, if NH happens, let's face it, it does lead to SS. So it's like a lose-lose situation. But yeah, I'm sorry but that will really damage the series a lot in my opinion. The problem is that the series has been pointing out the romance aspect, so now we know that is part of the story as well as being a factor of it. It's no longer just a battle Shounen. That said NS has been hinted to no ends. When that happens, it's hard to escape from that.
Now look, I could understand that SS could have work because of the premise. Here's the problem: the premise isn't the same as your usual one. First of all, Sasuke has not once have a close friendship or demonstrate strong bond with Sakura. In the other premise, it does. Second, Sasuke don't have a childhood relationship with Sakura to make it valid and make you feel sympathy with Sakura that her childhood friend turned evil. The actual premise does have that. Third, Sasuke must show at least three times that he does still feel close with Sakura but he is too dark, so therefore, his mind is on the wrong track; unfortunately, it's not there as well. He has shown no remorse or any care for her. Guess who though? Naruto. Yeah, wrong guy? Fourth, the character must have one person to focus on love, let alone only have one guy to speak to; therefore, she has only one direction. Sakura has two directions: Naruto and Sasuke. Therefore, she has more paths to choose and it's not given that he will be with that one person if she has another to choose. Lastly, Sakura is not THE main character, it's Naruto, who is in love with Sakura. Sakura's character is about learning the reality and correct the mistake.
It's been a while ranting on SS but I can go on longer. For now, I'll just stop there.