It was his own personal problem. Gershwin didn’t care, and neither did Irvin Berlin nor Cole Porter. Being a purist can be a pain to everybody else.
Indeed...and the way Mechanical Royalties and Performance Licensing works, there’s $$$$ in having other people sing your songs.
I even get a few cents every time someone downloads one of my songs off the Internet.
Of course, it takes forever for it to add up to a REAL Paycheck! LOL!