The problem is this works only with 2 parties that have already agreed to, and are willing to use, encryption. How many websites, services, and other sources of email have an option to encrypt your email to you with your public key? Not many at all.

I've stopped putting my public key on emails I send, because almost no one ever encrypted email to me, unless they were specifically sending something perceived to be sensitive.

Give me your key and I'll send you one ;)

PGP needs to be more easily accessed by non-tech folk.

Absolutely. Some of the biggest failures in security is lack of ease of use by and large, in addition to ignorance. I think most people are willing to do the proper thing, but they'll actually do it only if it's easy.