I THINK THE THEME HERE IS BANNING WHAT SEEMS LIKE ORDINARY COMMERCE

This post at the Cato blog talks about the burning questions of whether or not state and local governments should protect their citizens from the dangers of self-service gas stations and food trucks by banning those forms of commerce.
The issue with the food trucks was not, apparently, whether they were a health or safety hazard.  No, the issue was their threat to the businesses of restaurant operators.
The self service gas station ban is a mystery to me.  I can’t remember how long ago it was that gas station attendants disappeared around here.  There are places where they still exist?
The food truck ban is obviously protecting the economic interests of a narrow constituency.  The self service gas ban doesn’t seem to have even that justification.  
Why should governments be banning commercial arrangements that are obviously no threat to public health or safety?