This. A result of the proverbial revolving door between regulators and the banks. You can have regulations up the wazoo and it won't make a spec of difference if they are not properly enforced. Even with the odd criminal conviction bank regulation is kabuki theatre for mass consumption. These guys get away with murder - literally. EDIT: yes, literally the murder of thousands in Mexico. HSBC bank & Sinaloa cartel. HSBC in particular has a long history of enabling drug cartels. The Opium Wars.
Literally, hmm? I'd be quite interested to hear about these murder cases you allege (who murdered, who died, which jurisdictions and courts were involved, et cetera).