As someone who frequents the XB360E Known Bugs page on the wiki, I can't believe that there are people still complaining about the world size. This was announced a long time ago, months before the game came out, and they kept any quips about "infinite worlds" out of their marketing material, so you have no excuse for not knowing this before you bought it. Furthermore, it's something anyone who knows jack about this game and its massive RAM usage would have seen coming, because the 360 didn't have top notch hardware even when it came out seven years ago.
Stop complaining and deal with it, people. Splitscreen, SMP that doesn't require you to buy a server, the simplified crafting, and playing it on a big TV from the comfort of your couch should more than make it up to you. These are the kinds of things we buy consoles for, after all.