After NEM (which one assumes some non-Trekkers did see), there weren't going to be DS9/VOY/ENT movies. So the only viable commercial option left to Paramount was a TOS reset (I prefer that to reboot) for all the reasons others have mentioned.
They don't give a shit either way whether it's set the generation before or after TNG.
Never a truer word spoken. And precisely the point. They don't. It's a fresh start.