This is all my opinion. Some rocks dissolve in water, which is how we have sinkholes, or water table contamination. Another problem is physics, the hot water you pump down need to be pumped back up, that is a large cost on its own. Even if it is 200°C steam will rise in atmospheric conditions not subterranean, nor will it easily go back into the hot side pipes as this illustrates.

Funny enough I do feel geothermal is an untapped resource. I think, and this is my thinking again, a closed loop phase change system (like your refrigerator) can really work, even in areas where geothermal heat is not that readily available.