The main appeal of H1B abuse is cost effectiveness. If you ruin that by forcing competitive salaries (to even get the H1B in the first place), then that ruins the whole point (and companies are going to engage less in it, i.e. only when needed/"intended").

There is also a huge difference between dealing with a consultancy agency that you suspect engages in "creative visa workarounds" and straight up comitting fraud (=> higher risk, possibly even personal, makes for a much stronger incentive).