The thing is, there's no way to 'untrust' those protocols. With my GSM example, A5/0 is classed as an 'encryption level', but in fact is in-the-clear. With TLS, and a man-in-the-middle attack, there's no way to know if the MITM has renegotiated the encryption to be in-the-clear. There's no way to turn off support for in-the-clear. The worry about SSH is that with older crypto protocols, a weakness may be found, and that protocol will still exist in all versions off SSH. If the attacker/MITM can force a reneg of the protocol to use the compromised version, then it's as good as not using encryption at all. None of the above offer an option to disable all older protocols. This is a problem in my and the AC's eyes.
It could be that you mean to say "just use another program that supports only fresh crypto"...that is a viable option, but less attractive to one who has used SSH and finds its features very useful.