They can, but I can guarantee you that if your expectation is that every player is content with their personal goals being "kill the things the GM wants you to kill anyway," you'll completely miss the boat on a number of players. That doesn't account for things like "build a trade empire," "take over the keep of my father," "found an academy," "become head of my House," "see my daughter married off to a good man who can take care of her," "become a new incarnation of the Lightning Witch" -- all things I've seen players take for themselves.
Quite. And that list of end-goals can be very, very long indeed. Hard to design for all of them.
If you ask a designer to build a game for the goal, "colonize a continent", I'm guessing you'll get something that looks more like Settlers of Catan than D&D. And that's okay - Settlers is a popular game, after all. But Settlers won't flex so well to killing Orcus or becoming a god.
But, if I give you a toolbox that covers the low-level stuff, you can then use it for a variety of high-level goals.