I have no idea how wall st and retail banking got mixed up in everybody's minds. Stegall only allowed the two to be run under the same roof...
Why keep money in a mattress when the FDIC and its insurance is backed by the full faith of the USGovt? If you buy a share of stock well, that is different.
When you buy a share of stock, what does that mean? How is the value derived (of the share)? How does the system that tells you that value work? Most people can't answer these questions and yet invest money anyways.
The banking/financial system provides plenty of valuable services. That it also participates in value-destroying activities is always partially the fault of the consumers who want these activities to exist in the first place.