Other reasons for the S&L failure is in the name. When the gov't made it too easy for S&L's to do commercial loads there was a flood of "Banks" that converted to a Savings and Loan. Because they required less capital to write commercial loans they over did it and when the commercial market fell the S&L's quickly became distressed.
That's a good point. If my memory serves me correctly, the government allowed the S&Ls to underwrite commercial loans as a last-ditch measure to help them get out of that interest rate quandary I described earlier.