Have you actually looked at the taxes on an airline ticket? For example, you can buy a JFK-LHR roundtrip on VS for US$701.70. $502 of that goes to VS and $199.70 goes to various US and UK taxes. That's a tax rate of 40%.
I've not flown to the US for several years so maybe i've missed something, I most often fly EU-Russia and taxes appear to be a bit lower there.
That said, 40% is still peanuts compared what it costs to travel by car. Fuel is taxed something like 200% -rough guess- and then you have road tax, registration tax, ... I don't find air fares particularly expensive in this day and age, and its usually cheaper than any other way of transport even if you're not necessarily causing less pollution (not that that is much of a concern for me personally)
@ Mongo, I feel dumber just replying to you, but 1) my post is still there and 2) I there's worse places to be from than Belgium though I don't actually live there anymore.