Although the cheap admission price attracted some rowdies to the gallery seating, the majority of theatergoers who bought gallery seats were low-salaried working people who spent their discretionary income to attend the theatre several times a week. Thus they developed strong opinions about performers, plays, and production values, and they did not hesitate to express their pleasure or derision. They were called "gallery gods" partly because their seats were the closest to heaven and partly because of their power to advance or destroy stage careers.
The Historical Dictionary of the American Theater. James Fisher.