Why not even a self-signed HTTPS certificate?

Well, hello!
I was quite baffled when I saw that on register/login there was no HTTPS per default. But after manually addressing https://forums.debian.net.. Unable to connect..
I understand that buying a decent certificate may be expensive. But I don't see any reason not to offer HTTPS with a self-signed certificate..
Could someone explain this to me?
best regards,
daedalus
I was quite baffled when I saw that on register/login there was no HTTPS per default. But after manually addressing https://forums.debian.net.. Unable to connect..
I understand that buying a decent certificate may be expensive. But I don't see any reason not to offer HTTPS with a self-signed certificate..
Could someone explain this to me?
best regards,
daedalus