They would've dumped it very fast in the 70's, 80's and 90's as well if they had the access to all the things we have now. Trek came at the right time to capitalize on a changing culture and it helped being the only game in town.
I don't believe Trek will ever again have the long term success in had over those thirty years. For a long time, it was King. But all King's eventually die.
Except Shakespeare of course and don't forget the Almighty.