…which could be used to run from them considering that both Thors and to a lesser extent BC slaughter Tempests.
Usually running from BC ends badly (due to TJ) which brings back the Mothership in play for extra Recalls (on top of 5-Supply junk you have to add a 8 Supply junk just to stay alive…).
There is a reason on why Protoss counter Mass-Thors with Mass-Disruptors.