I hear this statement all the time, but no one actually defends it. They just state it as received wisdom.
I reject that received wisdom. If you want me to take it seriously, defend it.
What defense is there? That these types of questions come up every 20-30 or so hours of game play time as an estimate? It's rarely anything big, it's just me saying that they've misread the text or that the player doesn't know which way I rule something. The former happens now and then with my casual players, the latter is relatively common when people are leveling up.
So where's your evidence that it's extremely rare?