If I remember it correctly, that "profit" was nominal, i.e. without including the devaluation of that money due to Inflation, much less doing the proper investment accounting (as the Finance types do) were profit is a yield above a risk free investment (which, curiously, is normally Treasuries) and if it's below that it's not a good investment and beyond this the risk of losing your money also determines if the yield is worth.

Pretty much by definition the yield wasn't worth it in helping the banks at the interest rate the Government got, as why nobody else was willing to lend them the money at that interest rate.