It was also prohibited to use full flap because they kept getting stuck down. Which is a real problem if landing away somewhere where there isn't an onsite maintenance facility as you can imagine!
I submit that if your flaps keep "getting stuck down," then you don't have very good maintenance at your home base. Forget anywhere else.
When the rental agency tells you not to lower the flaps in case they get stuck, it's a good time to rent some place else.
"Doctor, it hurts when I do this." "Then don't do that."
Not really a workable solution to a mechanical problem, in an airplane. Flaps are supposed to be able to go all the way down, and come all the way back up again, on a regular basis.
I once flew with a gentleman while checking him out in a company Cessn a210, who insisted he wanted to leave the landing gear down. His theory was that if we never raised the gear, it could never fail to come back down. While I can't faul this logic, I insisted that he raised and lowered it for every trip around the pattern. Imagine an instructor ingraining a bad habit like not reaching for the gear handle every time!
Let's face it, bald logic suggests that if we never move the airplane, it will never break (it's not true, of course), so flaps that never go all the way down can't get stuck, gear that never comes up won't refuse to come back down, and engines that never get started will last forever, right? Wrong, all three counts (yes, gear that doesn't get retracted can still fail, but that's another discussion for another time).
If you find someone is telling you not to do something in the airplane because something keeps failing, sticking, burning, frying, or unusual procedures or maintenance are used to correct a normal action, then it's really time to go fly something else.