For some odd reason the NFL stuck at 53 man rosters and NFLPA is okay with it. I agree with your sentiment but until the NFLPA stance changes this we'll just see what have been seeing for awhile.
Most QBs have some form of trade value, I mean Nate Peterman has a NFL job. So some team might like Fromm's potential and give us some low round pick for him if worried can't get him on the waiver wire.
On paper it's New England yet they've been a little injured in the preseason and have questions about Cam at QB yet if Mac gets in there and can just be average they could be tough as like their RBs and TEs and you can never dismiss a BB defense.