If the government wants to get money from taxes, they will find a way to do it.
Say for example the taxes cause airlines to go to a 2x/day frequency with 250 seat planes, thus saving the airlines money in reduced taxes. Fast Forward... Now the government says, the people want more frequency so we are going to give you a tax break for each flight per day you have into XYZ airport. Now they shift back to the current system.
Now I agree that 2 mainline flights per day is better than RJs scattered everywhere, but if you think that the government gives a hoot about passenger frequency / your pay / cost of oil, etc you are sadly mistaken. They care about one thing, and thats collecting your money in the form of taxes.