The fees are high because there is a very real possibility that they will not be paid. If the initial case went badly or they lose the anti-SLAP then they wil get nothing. The will not stiff Bruce with the bill.
As for the nearly 900 hours - well that's how much work you need for due diligence, filing motions, etc. To prepare a successful case in the USA.
The law is for rich people, the poor get regulations, fines and jail.