"SIM cards as private keys?" This doesn't seem a good innovation where security is of utmost consideration. I cannot imagine holding my private keys in the open public where anybody could just snatch it from me. I cannot imagine putting my private keys on a table in a coffee shop or in a restaurant or in places where if you forget about it when you leave you might not be able to have it back.

This seems to be a try-hard attempt just to make Bitcoin relevant at the expense of something which is more important.