Did he?
-------

Looking over an early version of the script, it seems that there’s nothing to indicate that Luke did *not* bury or burn Beru and Owen’s remains. 

The scene where he sees their bodies ends thus:


> LUKE: Uncle Owen! Aunt Beru! Uncle Owen!
> 
> Luke stumbles around in a daze looking for his aunt and uncle.
> Suddenly he comes upon their smoldering remains. He is stunned, and
> cannot speak. Hate replaces fear and a new resolve comes over him.

After that, we switch to Darth Vader, and then back to Luke burning the Jawas. Then, next thing you know, they’re going to Mosy Eisley. Watching *A New Hope* confirms this order. **There is no indication that Luke did not deal with their bodies in the interim.**

In fact, there’s reason to think he might have dealt with their remains. From the novelization:  


> Not that the desert scavengers wouldn’t have been equally efficient in
> picking the burned-out sandcrawler clean of flesh, but Kenobi retained
> values most modern men would have deemed archaic. He would consign no
> one to the bone-gnawers and gravel-maggots, not even a filthy jawa.

If Obi-Wan was unwilling to allow the bodies of the jawas to be desecrated, it seems unlikely that he would simply neglect those of Luke’s aunt and uncle—unless, of course, Luke had already dealt with them.  



Now, in Legends, Luke did leave them behind, and buried their bodies after the Battle of Yavin, as detailed in the comic [*Star Wars 7.*][1] But in canon, there’s no reason to suppose he just left them lying around. 


  [1]: http://starwars.wikia.com/wiki/Star_Wars_7