>What's being discussed is whether it's worse than HTTP. It isn't.
I disagree. The self-signed cert approach tries to carry with it the trappings of proper HTTPS, but it results in a bigger attack surface. Every additional bit of complexity that can be added to describing the "safe browsing experience" to the end user is an additional chink in the public armour. This is why I originally called it "open users up to social engineering attacks to make my web-dev life easier".
Since the self-signed cert is not secure, admins should have no reason not to simply use HTTP. In fact, this is where the discussion has gotten to now: self-signed certs can't even do safe login. What makes the self-signed cert worse is that for some reason people are insisting on using it anyways.
Using a self-signed cert. isn't secure. What's being discussed is whether it's worse than HTTP. It isn't.