One did, then some moron thought "Hey! I know just how to piss everyone off and kill quite a few of our subscription base! Take away the free class system and make them choose a class, then everyone can be Jedi!"
The thing about Jedi are that... they suck against an experienced Bounty Hunter. Also, it was considered a great honor to be a Jedi when you had to work your hardest for it, all the guys that did it way back when it was finding holocrons that would show you the way, yeah, all they got was the ability to glow in the dark and a robe, a robe that didn't help against the Bounty Hunters. They also took away the ability to dual class such as Commando/Bounty Hunter, I could no longer have a flamethrower and rocket launcher, I had to choose. Not even Sophie could choose between that. You couldn't even choose the skills you wanted anymore.
And that game was... Star Wars Galaxies: An Empire Divided.
You see, you could be anything and even cross classes. You could choose what skill you wanted and follow your path to the class you desired and even revert at any time if you didn't like it. You could be a Weapon Crafter and Smuggler, an Entertainer and Commando. You could wield a sword or be a martial artist, you could change people's hair and eyes to make money, you could dance and ask for tips, you could purchase a house, place it where there's people wandering through and have saud people wander in and buy from an NPC you set up to sell gear you don't want or made. You could even decorate it by placing a couch upside down and on the ceiling if you wanted to, that was the kind of game it was. But not anymore.
I haven't seen a game like it since, Fallen Earth seems to have a free class system, but nothing like Star Wars Galaxy. May have been that everyone was their own unique self when it was around, you made this choice, you weren't cut from the same mold, etc. You could play as and create/design a freaking Wookiee, Bothan or Mon Calamarian -- three of the ten species you could choose. You can't choose your species in Fallen Earth, that's the only real reason I can figure it out as to why it's not the same, the lack of vibrancy that Star Wars Galaxies had; all of those species running around and working together, even speaking their own language until they opt to teach it to you.
I would like to see more games take up this free class system and environment in single player, but if they could pull it off like Star Wars Galaxy once did, then by all means make the MMO with it.