[tekromancr]

You need WAY more than just electricity. In order to have any chance of receiving any amount of bitcoin, you also need specialized equipment, connection to the network, and access to a mining pool.

Those three things would give a government interested in banning cryptocurrencies plenty of leverage to disrupt mining operations in their country.

All they would need to do is regulate the import of ASIC mining hardware; sinkhole any traffic that looks "bitcoin-y" (damn the collateral damage, we're fighting fascist communist pedophile terrorist drug traffickers here!) and similarly block access to any known mining pools.

They could go even further and introduce severe and draconian penalties to anyone producing, possessing, or using cryptocurrencies (which of course would be selectively enforced).

At this point, once you factor in the real-world element, the fact that, in theory, you only need electricity to produce bitcoin becomes such a small part of that equation.

I think at that point why not use PoS (or better yet, a DPoS scheme), if there isn't any real-world benefit to PoW? I think the tradeoff of introducing a small amount of revocable trust in exchange for RADICALLY reduced energy consumption is pretty clearly worth it, given the real world constraints.