When Star Trek, (T he O riginal S eries ) TOS there were die hard supporters. People who loved the show, the characters, the technology and would discuss every aspect.
When TOS went off the air, the fans remained. Eventually there were Movies with the Original Cast, then came Star Trek, (T he N ext G eneration) TNG. This was a different cast, a different time.
Some were a bit chaffed by changes, but it wasn’t mega.
There were movies with the TNG cast and another Star Trek came out, this was (D eep S pace 9) DS9 a space station with a different cast, although being in the same Era as TNG there could be cross overs.
Again, there was some chaffing, but not much.
Enterprise soon came, and it, being set before TOS had its glitches, it’s arguments, but nothing devastating.
Then, Star Trek Discovery or as many call it; STD.