"If there's a bright centre of the universe you're on the planet that it's farthest from." One of Luke Skywalker's earliest lines. Our galaxy contains at least 200,000,000,000 stars. The Andromeda galaxy contains over 1,000,000,000,000.
Taking all this into account, why why why why why do we keep going back to fucking Tatooine? RotJ was understandable, it made sense both for the plot and for Luke's character development. But the amount of shit that has happened there according to the prequels and the expanded universe should make it one of the most well known and important planets in the galaxy, not the obscure backwater it is supposed to be. You don't even need to come up with new planets if you suffer from the utter lack of creativity this tendency indicates. There are plenty of interesting planets already established that the films have never even mentioned. Mandalore, Manaan, Korriban, Ziost, Rhen Var, Dromund Kaas, Tython, Ryloth, Bothawui, Nar Shadaa, Mon Calamari, Lehon. But nope, it's Tatooine, a-fucking-gain, and I'm willing to bet we'll visit Yavin IV, Hoth, Dagobah, Bespin and bloody Endor again (all of which are also supposed to be obscure backwaters that people keep visiting and where important events keep happening).