Obviously, Spock is not actually a Vulcan, but a human mutant who got his mental powers by opening and eating the brain of a New York city Detective who is constantly getting high. The Incredible Hulk procreated and gave birth to generations of big green babies. Romulan Macross Missile Massacre Maneuvers obviously cannot stand up against the power of Federation Beam Spam.

And there are at least 3 alternate continuities going on. Original Star Trek, Alternate univrse 1 Star Treck (where Old Spock [Spock Prime in credits; does this mean he has the power to punch the 4th wall and retcon the universe? Well, obviously he does, since it happened and he was involved...] came from), and Alternate Universe 2 Star Trek (where the movie is set).

Damn Enterprise and its stupid 'Temporal Cold War'. That's the only explanation for how that world grew unstable enough for that to happen. Where was Q when this was happening, may I ask?