There's actually a mechanism to this and you hit on it.

It's the same reason Exxon is okay with a carbon tax, but not a carbon market.

Taxes can be worked around through their lawyers, but a full blown regulatory system would require them to invest in buying even more bureaucrats and regulators than they already pay for.

Literally just taking their money is more predictable and accountable. Because of that, it's easier to navigate around them.