The trouble is that the market rate for professors in other subjects is not as high, and they get mad if the differential is too great.
But, yeah, the delta between econ/law and CS faculty salaries is why I turned down TT offers and went to industry.
They can pay. They're choosing not to.
Also, econ/fin/law makes more even at undergrad only institutions. It's a perception thing with admin. ESPECIALLY at those places, until institutions pay CS profs market wages, stay away unless you want to wake up when you're 60 and realize you can't afford to retire like all your grad school friends and so can't spend as much time as you'd like with your grandkids because you're teaching courses every semester.