Why isn't there an effort to detect MITM proxies and post equally scary warnings? Surely users have a right to know.
MITM is worse than self signed certs and if 'exceptions' can be found for MITM like corporate security, management etc then the same exceptions should be found for self signed certs for individuals rather than creating dependencies on CA 'authorities'. This just another instance of furthering corporate interests while sacrificing individuals.
The scary warnings for self-signed certificates are in fact a protection against MITM. It's because of them that MITM proxies are forced to install a CA certificate. The main difference is that installing a CA certificate requires explicit action in the browser (and on some newer systems displays scary warnings), while if a MITM proxy could simply present a fake self-signed certificate, it could easily intercept anyone. Therefore, self-signed certificates are strictly worse.