The reason that the vast majority of rsync.net is not covered by https is because I personally have not yet decided how I feel, philosophically, about the notion of https-only websites.
As silly as it may sound to you, I very much like the fact that you can read rsync.net HOWTO pages with netcat. Or telnet'ing to port 80. Or grab them with old versions of 'fetch'.
I used to do all kinds of interesting and time-saving tasks on the pre-https internet with simple, static UNIX tools. As you can imagine, almost all of those workflows are now either broken or require a big huge pile of python libraries.
So in summary, I am sorry to deprive you of your righteous indignation. You can see from our properly implemented order form that we understand https just fine, thank you.
The real answer is that https-everywhere sounds like it's probably a good idea ... but also sounds like you should maybe get off of my lawn ... but I'm not sure yet.