對，君子不立危牆之下！又不是不要給錢，為什麼要自立危地？

I don't deny your comment is 1 of the many reasons. I think the most important reason is :
(1) They are too friesh in this industry, they have no connection to join the sauuna.
(2) They are fresh there, no money to pay for the deposit. They need "Training fee, uniform charge, deposits, etc" It normally comes up to a few thousand as a start up cost.
(3) They are controlled by "wolf dog", to stay there which is within the controlling powe of these "Wolf dog".