Part of the reason they actually rescaled things is because of the light speed theory put out by Hawkings back in the early 80s.
It wasn't purely a cosmetic change, it was in part because going back to Star Trek through TNG gave TPTB the opportunity to try explain things more accurately as we understood the light speed threshold barrier theories then. Since then though, our theories have changed a lot (again).
Star Trek has always been really good at trying to introduce pseudo accurate scientific concepts through the series almost as a way of teaching while entertaining. Sure, we can't claim a lot of technobable is super accurate, but at least a lot of it has some basis in reality.