Jedi were rare in the beginning because not a lot was known about the method for unlocking them.... soon people shared all the information about the Holocron grind, basically you had to master 3 (I think) separate professions they where randomly picked and you could use holocrons to tell you how close you where...
Some people got lucky, and only needed to master several basic professions... others weren't so as I remember hearing about a guy who had to grind every single profession tree in the game to get his unlock. But soon everyone was working towards it and they became more and more common.
Again in the beginning it wasn't so bad... Padawans sucked and could be easily killed, if jedi used there abilities in public they where flagged as a combatant and anyone could take a pop... there was also perma death... they got killed, they stayed dead and had to start again! This was awesome! Especially when they added jedi player bounties for us bounty hunters to get stuck in to. But it was flawed, the holo grind became to easy for experienced players and with the removal of perma death Sony wanted a more interesting way of doing things so they gave us the village!
Again if anyone wanted to do it they could, padawans where still easy marks but higher level players where too over powered and so Sony started ruining other combat classes in a useless attempt to balance the game again.
I eventually went Jedi, right before the NGE and was furious when it became a starting profession... it was still over powered compared to the other combat classes at the higher levels and the game just became "Jedi Wars" There was no, being a dark jedi, joining the sith or the emperor etc it was all poorly thought out!