I understand that all of Peel Airports incl MME are now owned 65% and operated by a Canadian airport operating company (VAS, which is jointly owned by Vancouver Airport Authority and Citi Infrastructure Investors, operates 16 airports around the world.), and the introduction of the development tax is since that acquisition took place. Vancouver airport collects a Development tax on departure, which has to be paid at a cash desk before departure, as was the case at Montreal the last time I was there (all flights on BA). I was making the point that this is possibly a more acceptable practice in Canada, especially as displayed prices for most things need taxes adding (which vary from province to province), and a service charge is often expected to be paid on top. so perhaps the MME owners mistakenly believe that such practices are normal and acceptable in Europe.
note re Carribean reference - VAS also own Nassau.