I wonder if this means flying out of the French side of Geneva airport would incur the fee while the Swiss side would not?
(Edit, it seems like the French side no longer exists after Switzerland entered the Schengen).
If it's the former, it's still lousy because they're advertising lower prices than what the actual cost is.
But even so, it's still not much different from retail stores charging sales tax. Personally, I think it should be illegal to charge sales tax after-the-fact. The price advertised should be the price you pay, period. In Europe, this is exactly how it is: whatever price you see advertised is what you pay, and that's all. There's taxes (15% VAT I think, so not trivial), but they're built into the price, and they're not allowed to advertise the pre-tax price. This is exactly how it should be.
Convenience fees are basically dark business method patterns.