Not to get off topic, but is very shver to use the Rambam as a proof for kollel. When he says that anyone can join shevet Levi, he means to teach Torah, not to sit and learn.
Plus, the Rambam also clearly writes than one cannot receive money for learning.
Chareidim started a movement when learning in kollel is the norm, going against the status quo of hundreds of years of Jewish history!