When I was a kid my piano teacher discouraged playing by ear. She stressed reading and memorizing the notes. I trained myself to play by ear later.

I'm glad I learned to read, and I really enjoy playing by ear. I would hate to be without either skill.

In another forum I visit (piano world) many of the members are academy trained pianists, and several of them are piano teachers. One of the most frequently discussed topics is "how to learn to play by ear". So yes, those who are a slave to the sheet music are envious of others who can play by ear, and they spend a lot of time and money searching for and buying the music for a song they want to learn.

I wouldn't attempt to play "Moonlight Sonata" or any other classical piece by ear, but if it is a popular song, it's easier and a lot more fun to play by ear.