Nardpuncher
Rear Admiral
Yep, I think Lucas forgot that Obi wan was disguising himself in the first movie and so went on to make the Jedis all dress like that. Ugh.His costume made the most sense. In Star Wars, Obi-Wan wore the same style of clothing as Owen and other people on Tatooine. It was desert clothing. Even the Jawa's wore something similar.
Luke's Jedi costume could be more along the lines of what a Jedi Knight wore. However at the end of Jedi and the prequels it seems all Jedi Knights wear desert clothing. I'm not quite sure why that is.
Neil