Comment by ekr____

This has a number of negative downstream effects.

First, recall that links are very often inter-site, so the consequence would be that even when a server upgraded to TLS 1.2, clients would still try to connect with TLS 1.1 because they were using the wrong kind of link. This would relay delay deployment. By contrast, today when the server upgrades then new clients upgrade as well.

Second, in the Web security model, the Origin of a resource (e.g., the context in which the JS runs) is based on scheme/host/port. So httpt would be a different origin from HTTPS. Consider what happens if the incoming link is https and internal links are httpt now different pages are different origins for the same site.

These considerations are so important that when QUIC was developed, the IETF decided that QUIC would also be an https URL (it helps that IETF QUIC's cryptographic handshake is TLS 1.3).