I don't get why people hate the alternate reality thing so much.
The most sci-fi elements of trek (and not only trek) had always been influenced by what was contemporary at the time. There were certain trends, even, among different 'futuristic' products consistently drawing inspiration from each other.
Concepts like time travel have evolved well past the "back to the future" narrative because quantum mechanics is more contemporary now and is considered a tad more realistic.
We can't fault a creative team of our era for taking inspiration from what they know
now, and ostensibly expect them to be..outdated.
Now, putting aside the fact that it is all moot points if you are making excuses for what Tarantino is saying, because it doesn't matter what happened in tos since he'd write for this trek and he must thus follow THIS canon, jj&co didn't invalidate previous iterations,
anyway.
They didn't really contradict the time travel device used in previous trek, they just used
another device. No one says there can only be ONE device.
Parallel realities aren't new to trek either, if anything this reboot is just using one of the possible explanations of how they might be created or you can access to them (through a black hole. There are actual theories about that).
As for spock/uhura...man, I don't get why romance and characters having sexual agency is so ostracised by some. Some fans aren't even that bothered by the destruction of vulcan but they can't get over two fictional characters being in love.
This is another tiring topic but jj&co did not pull it out of their asses. The reboot isn't saying they were an item in tos too, anyway, just that the hints in tos are enough to imagine that, had they met under different circumstances, it's possible they'd become a couple.
Kelvin trek is another reality so pointing up that things didn't happen in tos is a contradiction. Saying 'I don't like it's another reality so I'm going to ignore that because tos did time travel differently' isn't an argument, it's being dishonest by deliberately ignoring the thing that invalidates your main criticism making it pointless.
Besides, it's disingenuos to ignore the fact that it's mainly the context of the 60s that made a romance impossible in the original thing.
Roddenberry
had tried to set it up from the get go himself, but racism wouldn't make it possible for them to have an interracial couple in the series.
(* and I'll point up the attraction was MUTUAL as evidenced by his reactions, not to mention the scene where Kollos not only confirmed that Spock saw Kirk and Bones as friends, he also found Uhura beautiful and he was enough interested about her to look for the meaning of her name in her African idiom AND he read poetry thinking about her)
As for Spock being incapable to have relationships or feel love...I agree with
@fireproof78 : it seems rather inconsistent as a headcanon by itself because we know that even the vulcans have relationships and love, so it's a mystery why some fans want to believe that a half vulcan guy cannot do that 'because he's vulcan' .
Roddenberry, anyway, had wanted to end it all with him getting married, they never intended or suggested Spock was asexual and/or aromantic.
If this part of Spock's story was left ambiguous at best or, more correctly, severely underdeveloped, it's no doubt because of the influence of the time as well eg. main guys couldn't have girlfriends because women made them less 'cool'. The fact Spock was the nerdy friend of hero trapped him into annoying clichés too (nowadays writers aren't scared to show that nerdy guys and introverts can have relationships too and thus a life outside their best friend, even if the latter is the main guy. Characters can be more layered than alien=weird and human=conventional and normal )
I think Spock had issues with love just like he had with admitting his other feelings too. It wasn't about him not being able to experience them, but more a matter of him being on denial about his real self and having to accept that he wasn't this unfeeling, cold logical guy he wanted to pretend he was.
He didn't admit friendship either but still, he clearly experienced that (funny those who think he can't have a romance because he's vulcan don't realize friendship is him experiencing feelings too, btw. Nice double standards, bro)
Kelvin Spock evolved sooner because of his life experiences. He is positioned more as the Spock you saw later in the movies than the delusional guy you see in tos. The result is a man who is more honest with himself and he doesn't pretend he has no feelings. He also is more defensive about his human side because he genuinely respects humans thank to the influence of his mother (and later Uhura). He is more contemporary as that biracial guy allegory he always was, tbh.
Tl dr: it seems like some hate JJ&co because their trek isn't. .outdated.
And yet, the main purpose of a reboot is to upgrade things. And I don't mean just the special effects, clearly.
The 'anti alternate timeline' arguments also seem to paint the most conservative fans into a corner: a reboot clearly cannot be a copy of the original thing, the writers need to change some things a bit to make the story more unique and unpredictable, and if you don't make it another reality then you need to retcon the old thing ..and fans don't like that either.