Kind of a fair point though I think users should be able to make that choice for themselves. If they do not want that, they can just not use it - the app clearly shows whether chats are encrypted or not and I'm pretty sure you could also disable the plain-email feature.

I feel like Delta Chat should be mentioned here as a secure, decentralized and pretty awesome alternative.

It also allows to communicate with non-delta chat users via email through the same chat interface