Ban State Entry Road tax for commerical vehicles (taxies/buses/...)

Many state governments of India tax the entry of other state registered commercial vehicles (taxies/buses/...). The tax depends of number of seats in the vehicle, the number of days the vehicle is in visiting/passing state. This is a huuge setback for tourists since they are already paying high price for commercial vehicles to travel to tourist destinations. Why should state penalize vehicles when 90% of the time they are passing through state or using national highways which are already tolled? Does gov't of India want to promote tourism? Should tourist be paying so much for passing through a state on a tolled national highway? Why shouldn't there be a all India OneTime/Lifetime Tax? And the rest should only be tolls.