Writing about the new Star Trek film from planet Corner, Mark Kirkorian identifies the true danger of time travel:
I don't usually like time travel stories, ranking them just above holodeck cop-outs, but in this case it served a long-term purpose. Among Trek fans and writers, it's always been the position that only the TV series and the movies were "canonical" — i.e., genuine events in the Star Trek universe, while the novels and comic books (not to mention all the fan-authored stories) were not. But this movie has created an alternate timeline, and thus the possibility of an infinite number of alternate timelines. So instead of a Star Trek universe, there's now a Star Trek multiverse, where everyone's story (even the fatuous Kirk-Spock love stories) can be "canonical," because they take place in a parallel universe!
So lay off the time travel, OK guys? Unless you want to spawn an infinite number of parallel universes including a few in which you are gay!