Great question.
The better pitch is to consider the "tax" like an additional permit with increased costs, including mandatory more expensive insurance. It's the cost of doing business, wrapped into your overhead. The disparity between the large pickups and the smaller sedans of yesteryear are staggering; imagine if you could buy and operate a semi truck with the same costs and licensing as a sedan. Trailers parked in front of your house completely obscuring the street, or taking up extra spots at the grocery store. People who don't know the size of their vehicle knocking over signs and mailboxes. More roadkill, dead pets, and pedestrian fatalities because there are so many blind spots for such a big truck.
Obviously, pickups and semis are still quite different in size, but the point is that pickups and large SUVs are now so much bigger than sedans--bigger than what we built our streets and bridges for--that they present additional danger.
- Larger vehicles cause more wear and tear on the road just by driving on them
- collisions and accidents are more destructive and fatal due to the more deadly shape and weight
- blind spots are bigger, making the vehicle more dangerous for anyone outside of it
- effects of distracted driving are compounded
- irresponsible drivers get to drive these larger vehicles without any additional barrier to entry
In short: these machines can be used to perform specific tasks, but they are not the same size, shape, or weight of our lived environment. Additional regulation is needed to offset the real effects on people and infrastructure (e.g., more difficult licensing, higher registration fees, higher tolls, etc.).
I'm not quite sure what you mean by "regulation". Increasing the cost, such as by mandating higher and more comprehensive insurance, or instituting a gas tax are both regulatory measures.