darklordoftech said:

No matter what Luke's ROTJ clothing was or wasn't meant to be, what Obi-Wan wears in Star Wars (1977) definitely wasn't meant to be a Jedi uniform. What Obi-Wan wears in Star Wars (1977) isn't what commoners across the galaxy wear, it's just what Tatooine moisture farmers wear. Look at the commoners on other planets if you don't believe me.

Well, here's what a moisture farmer on Aduba 3 looked like in a comic from late 1977:

Now I realize that these comics have a somewhat dubious canon, but it goes to show just what SW lore was as early as in 1977. This was also the only character I could find a proper picture of, but the other Aduba-3 farmer pretty much wear the same outfit as Owen Lars did.

Also, here's what the old Jedi knight Don-Wan Kihotay (terrible name btw) looked like in the same comic:

It's kind of cheap, and lazy. Or perhaps this is what Lucas always intended it to be, I don't know. But it's not exactly like Abrams is screwing over the lore by giving Luke a Ben Kenobi-style robe rather than a black uniform. You can really stretch the lore any way you want with this, and the new Luke outfit is consistent with what we have seen in both trilogies so far, as well as some of the EU.
I'm personally just going to go with it. The black outfit would have been cool, but the new white one works just as fine. I think anyway.