Kwaiker(Joe), the parnossah mentioned in the Rambam’s havtochah is not squeezing money out of the unwilling public and causing a major Chillul HaShem. If the Israeli public did not mind, it would be fine.
Sam2, we don’t pasken like that Rambam. Look in Hilchos Talmud Torah in Y.D., in the Shach there.