When the game first came out before CU/NGE there was no ability to jump at all. Not sure why, just the way the game was set up. At the time SWG was the first MMO i had ever played so I don't know if it was the fact that I just didn't notice or the fact that the game was geared in such a way that it was not needed. Either way it was not something i noticed at all. Now, on the other hand, it is a completely diffrent story. Nothing is more annoying then watching your toon jump up and down like a sad cheerleader that couldn't make the varsity team while you are trying to chat with someone. I guess once the devs decided to dumb down and WoWify the game they decided that we needed to be able to jump if for no other reason then to say that we could.
Just my two credits.