How do you determine the keys associated with the people you wish to communicate with? (The web of trust and going to key-signing parties are about a thousand miles from 'everything just works'.)
I agree with you that if you want to actually improve the security of the people who are right now not using any encryption, make encryption easy to use. Even if this means that it might not fit the threat-model of those targeted by state-actors.
IMHO, PGP could actually be used for this (even if it might not be the perfect fit) by using Trust On First Use, better interfaces and more integration into mail clients. The problem is that it is right now a tool used and made by those who want really strong security. This includes e.g. encouraging you to set a passphrase, which makes it more secure, but also more of a hassle for most people.
[1] This is obviously only true if you don't fear it being compromised / your security requirements are low. But then, if you need strong security, use full disk encryption and Qubes or something similar.