I'm fine with people objecting to gas taxes because they're regressive, but a VMT tax is also regressive. And suddenly instead of having to have enforcement/collection on a few hundred or thousand gas stations, you have to have an enforcement/collection bureaucracy on every single licensed vehicle.
The gas tax is a nice simple tax, easy to enforce, which has all the incentives going the right way. A VMT tax is a needlessly complex way of trying to get the same money. Just make it stop.