The original trilogy WAS Star Wars from 1977 to 1999. It is also much more widely critically acclaimed and uncontroversially appreciated by fans than the prequels.
I'm not saying there isn't more to Star Wars than the OT, but it's not exactly weird that Disney would choose to focus on it.
I don't expect Disney to start taking drastic chances with the franchise until they make back the 4 billion they paid for it. And even then, I expect them to play it safe until they hit the point of diminishing returns.