Sacred Ground returns lands you sacrificed to Smokestack
Quote for relevance. People forget that this enchantment basically turns off crucible/strip recursion and smokestack.
I'm pretty sure that when it comes to sacred ground, this is in the front of everyones mind. The only possible application for terra eternal is probably uw landstill, and even then it seems not so hot, unless you've got a goyf staring you down, in which case I'd probably still rather have a sower. Lets just throw terra eternal on the unplayable list and forget about it.