So, what DID kill Star Trek then, in your estimation? (Assuming, for the sake of arguement, that it was dead.)
Familiarity. Everyone who'd gotten interested in the 1980s and 1990s other than a few million hard-core fans got bored with it after a decade or so. Most of them, BTW, abandoned it mid-run of DS9 and Voyager - a couple of years after TNG left the air.
This has happened to a lot of TV series that were watched by far more people than Trek ever was, so it's scarcely anything to be surprised by.
The movie built on the vast majority of remaining hard-core fans, intrigued "lost" viewers who had perhaps grown a bit nostalgic (again, movie released in 2009; most TV Trek viewers gone by 1997 or so) and attracted millions of younger people and folks who'd never paid a lot of attention.