I remember a discussion here on HN about how it makes life very hard for organizations like a school in Africa where the Internet connection is slow and expensive. Although many requests go many times to same pages (e.g. Wikipedia), HTTPS makes it impossible to cache them with a local cheap proxy.

HTTPS is cargo-cult'ish in this aspect. One obviously should not accept or serve personal data over HTTP, but why to encrypt public information? (Having said that I'm guilty here too as I blindly followed the instruction given to me by my hosting company and my plain open site redirects to HTTPS.)