The approach you're talking about --- some people call it "key continuity", some people call it "trust on first use" --- does not work on the public Internet. At all.
The problem with it is that SSL/TLS is designed and intended to protect commerce. The attackers that commerce cares about†aren't targeted. If they can't sniff someone's session because they already established a trusted pairing with their bank, so be it! They'll just wait for the next person to connect. They will obviously get some percentage of user sessions that way, either from first connections or because people changed computers or reinstalled their browser or deleted files or what-have-you.
These are connections the attackers get above and beyond the stuff they already get by owning up machines. Which they'll also be able to do more of, because the same problem will happen with software update systems.
The current hardwired selection of CAs we have is bad, is a flaw in SSL/TLS/HTTPS even, but it's not so bad that we continuously lose X% of all connections to passive attackers.
†and that you should care about if you value the ability to run businesses on the Internet
The problem with it is that SSL/TLS is designed and intended to protect commerce. The attackers that commerce cares about†aren't targeted. If they can't sniff someone's session because they already established a trusted pairing with their bank, so be it! They'll just wait for the next person to connect. They will obviously get some percentage of user sessions that way, either from first connections or because people changed computers or reinstalled their browser or deleted files or what-have-you.
These are connections the attackers get above and beyond the stuff they already get by owning up machines. Which they'll also be able to do more of, because the same problem will happen with software update systems.
The current hardwired selection of CAs we have is bad, is a flaw in SSL/TLS/HTTPS even, but it's not so bad that we continuously lose X% of all connections to passive attackers.
†and that you should care about if you value the ability to run businesses on the Internet