Earlier quoted context omitted.
"The money stinks as a comic" A classic case of oversupply perhaps. Far too people quitting their day jobs to do stand-up full-time because someone in the office laughed at their jokes.
Everyone learns to perfect their craft through constant failure. Musicians/artists have the luxury of failing over and over while in the isolation of their bedroom. Comics have no choice but to fail repeatedly in front of a live audience, and nobody wants to pay you while you're learning to fail.
To paraphrase: your first 100 jumps off the board count if you hit water.