It is a very simple equation. Musician A has talent, an instrument and wants to play for people.

Venue X has a stage, sound system, and a number of other expenses. Venue X also has advertising and publicity people. Venue X is where people know to accumulate for music.

If Musician A is only interested getting up in front of people s/he should practice, work hard, and make a name for him/herself. Then s/he will be paid to perform. If Musician A wants to go someplace where there are others who like music, where s/he can enjoy a show, and be part (albeit a small part) of that show, where s/he can get some mike time and experiment with new material and hear others doing the same thing then s/he should expect to pay for the privilege. In a two and a half hour evening of entertainment Musician A only makes up about 10 to 15 minutes of the show. the rest of the time s/he is a member of the audience and like them, has to pay to see the show.