A significant part of the problem was that the S&L regulatory model of the 30s - 60s assumed low regulated interest rates and when the low rates could no longer be sustained, the response to that was badly handled by both regulators and the S&Ls themselves.
^^^
This. There were two S&L crises-- the first at the end of the 1970s due to Regulation Q (deposit interest rate caps) and the prohibition on variable rate mortgage lending; the second through the 1980s as a result of the deregulations enacted in response to the first, which resulted in moral hazard, excessive competition for deposits, and real estate overlending.
Indeed. Well said. The 1970's affair, where interest rates paid by banks/SL's were fixed, while market rates were higher, led to what is called "disintermediation" when mutual fund money market funds got going, and folks pulled hundreds of billions of dollars out of the banks/SL's. And that led to cash flow problems, since the SL's were stuck with a loan portfolio of fixed interest rate loans that fell far below market (in essence the value of their loans tanked).