Hp,
In my experience the Caribbean airports are the biggest offenders for stealth charging, but that is a government tax not a usage fee (even though govt & airport are one & same). Of course this is especially counter-productive as these are governments which spend a fortune marketing themselves abroad, and then whinge that UK APD is hurting them! And that is on top of the $20 fee for a 'local' driving licence!
But I digress - I'm much better versed on US airport funding than their northern neigbours but iirc tax was included in the price. I have been to Canada twice but never used their airports, so please do correct my ignorance here!
What has this got to do with MME? My guess is that they see it done at NOC, NQY & BLK as their 'inspiration' - but I don't think NQY or NOC are ever going to seriously base a/c?