Tell me if you understand the problem in its full simplicity: former regulators and public officials who were employed by the citizens to represent their best interests can use the expertise and contacts acquired on the job to benefit from glitches in the system upon joining private employment — law firms, etc.

Think about it a bit further: the more complex the regulation, the more bureaucratic the network, the more a regulator who knows the loops and glitches would benefit from it later, as his regulator edge would be a convex function of his differential knowledge. This is a franchise. (Note that this franchise is not limited to finance; the car company Toyota hired former U.S. regulators and used their “expertise” to handle investigations of its car defects).
I have several remarks.

First, the more complicated the regulation, the more prone to arbitrages by insiders. So 2,300 pages of regulation will be a gold mine for former regulators. The incentive of a regulator is to have complex regulation.