The browser should treat any HTTP connection as a MITM attack at all times, too. Actually, it should also treat it as multiple MITM because everyone in your network or in the path can see your traffic.
We could argue if it even makes sense to differentiate between SSL with self-signed certs and plain HTTP connections when warning users, I'll give you that. But in no way SSL with self-signed are worse than HTTP.
> Try to think through how else it could possibly work, and you'll see why the browsers do this.
The browser should treat any HTTP connection as a MITM attack at all times, too. Actually, it should also treat it as multiple MITM because everyone in your network or in the path can see your traffic.
We could argue if it even makes sense to differentiate between SSL with self-signed certs and plain HTTP connections when warning users, I'll give you that. But in no way SSL with self-signed are worse than HTTP.
> Try to think through how else it could possibly work, and you'll see why the browsers do this.
Funny :)