The bravery required to get up on a stage as an adult and play something for the first time, Should not be underestimated.
You may cringe at the result of their attempt, but I feel a charitable person would try to help or encourage them in some way.
It IS indeed "underestimated", as you say. I would love to one day get up on the recital stage, but just the idea of it - not the act itself - before anything else, is unbelievably paralyzing.
You've got to start young, right? And have the right teacher(s)!