A lot of meaningless hype by the airlines IMO.
A couple of years ago I was flying BWI -> MSP sometime in the summer; weather at BWI was clear as a bell, but 175 miles to the west there was a line of summer storms and due to reroutes/congestion ATC imposed a ground hold.
NW Captain from the gate explained the situation, said he wanted to taxi out to get in line and wait and asked passengers if anyone had a problem with doing so. No one did, we taxied out, waited 1 hour and ATC hold was lifted and on our way.
This is how it is supposed to work. 3 hours to return to gate is entirely reasonable. The airlines brought the rule on themselves by irresponsible behavior.