Except that achieving enough consensus to successfully hard fork bitcoin is effectively impossible. I mean seriously, they can't even agree on how to increase the TPS limit (increasing block size, etc.).
Bitcoin is now TBTI--Too Big To Innovate.
You don't need consensus.
There would be a fork, and two version of Bitcoin would coexist: the old one, and the new one with ethereum's features. The difference with the actual ethereum is that everybody owning BTC would now be able to use the ethereum feature set.
I'm very interested in the tech behind ethereum, but the ether currency has no future.
