Yes, geothermal is limited to places where there is heat near the surface of the Earth. If you live in Iceland, then geothermal makes a lot of sense.
Of course, there are some places where geothermal plants could be built in the US, and probably will be if the price of oil continues to stay high.
Nuclear plants can't be built just anywhere, either, as they require a steady and dependible supply of cool water. Of course, there are many places where nuclear plants could be built, but aren't, largely because someone is already living there and has heard of Three Mile Island. They don't seem to have heard just how many nuclear subs there are, and that there never seems to have been a problem with them.
Somehow, I don't see a nuclear plant in the Sonoran desert, but a solar plant might fare well there. By the same token, a solar plant in Seattle might be a poor idea.
We need to exploit what nature gave us, wherever nature gave it to us.
