>Shouldn't we want anyone to make all-new Need For Speed or Final Fantasy games?

We are currently seeing a microcosm of this in the indie space as we speak. I think the answer is a resounding "no". Not unless you can out-advertise all the fake or slop copies out there. The issue is less about the idea of building a moat and more about how it's clear that 99.999% of efforts will be anything but that.

>Or even if some random person wants to maintain an old piece of software that they didn't originally write: good!

Sure. That's pretty much done regardless of publisher intent. Modding is too much of a cat and mouse game to really bother with financially, and online games avoid it by owning the server to operate on.