Laura turned this over to me. In checking with engineering, as they are the ones that made the decision, here is what I have gotten back.
We discussed the fact that GWIA does not fallback to unencrypted transfer. We did not want to ever use TLS 1.0 without the admin explicitly "dumbing down" their system. The fallback to unencrypted transfer could be argued, but we never recommend allowing unencrypted.
So if you still believe that GWIA should fallback, please enter an enhancement request and let Mike decide if this is a decision he wants to reverse.