You have to get to the Continent in the first place, which costs money and more importantly, a great deal of time to allow for contingencies. So while I'm happy to use FRA as an intermediate stop (because the long-haul C flights are better priced there and I have reasons dropping in), it would be difficult to justify if you had no motive other than saving £44. per passenger.
It's another one of those 'oh, well' taxes that you can't avoid. It will be put to good use on buying plasma screens for the Government's core voters and other high-priority projects. It won't move flights offshore to an appreciable degree.
I liken this process to that of a ratchet, and doubt that the next government will have the testosterone to eliminate the revenue raised. Indirect taxes are less unpalatable than direct taxes to me, but it's complete suckage when both are increasing.
BOFH