That only touched on part of why a lot of us left SWG. The class changes were one thing--it did ruin how flexible the game had been. Grind your way up as a Droid Engineer and find that it wasn't too your liking (as in my case), you could 'forget' what you learned as a DE and start learning your way through Musician or Bounty Hunter. A lot of us would've forgiven the Devs that in the long run, even though we saw Jedi everywhere when before they were relatively rare (though becoming more common with a definite quest to become a Jedi instead of the original Master 'X' of the right classes for your character--every character had a different path).
But the biggest change was in the gameplay. Battlefield had just come out a few months before, and caused the inevitable hit to the playerbase which nearly every new game causes. And the vocal minority were wanting more Battlefield-like gameplay in the game instead of the traditional MMO-style target lock and cycle your skills. So you take a game where, up until that point, you were playing an MMO and then suddenly change the game into a 1st/3rd person shooter and say that it's better for everyone.
So of course a lot of us MMO players just up and quit. My entire guild decided the game wasn't the game they had joined and we up and quit. Had one last party, used up all of the ultra rare stuff we had sitting around, and shut down our city. At times, I miss the old SWG. Especially my party starship.
These were the biggest changes that were the death knell though, through a game rife with major and unexpected changes that weren't advertised. An early indicator of what was to come was during the transition from Beta to Launch. In Beta, Musicians and Dancers were a really big thing (I had gone Musician) and you could easily find a group of 4-6 people, or even 2-3 full groups of people playing instruments or dancing, plus a number of people hanging out and chatting. Every Musician and Dancer had control of their character, able to go off on a 'solo' before slipping back in with the rest of the group. We had a lot of fun roleplaying this out, of course.
It's how I met my guild, in fact.
On Launch though, the whole Musician/Dancer system was entirely different. Instead of free to control your character, your actions were locked to the Band Leader's. If they decided to go do a solo, they could, but you were just a automaton unable to do more than play the supporting music to the leader. Dancers were made the same way, though I was told in time that they were given a bit more flexibility--but the musicians weren't. Which totally destroyed the entire fun that we'd built during Beta, the roleplaying, the community. I ended up going Droid Engineer because they had destroyed a very fun part of the game for some nebulous reason of avoiding 'macro players' by encouraging people to join a band and do nothing to earn their XP.
*chuckles* Ooops, guess I still have a lot of repressed feelings about the way we got jerked around in SWG.