Controlador,
You are correct in your statement that the British, in particular, are poor as a nation in general, in learning a foreign language. We are, unfortunately miles behind other countries in this respect. There could be many reasons for this, but this is neither the time or the place to discuss such a matter.
However, if you are indeed a professional ATCO, then surely you can understand how dangerous it is to talk in something other than a common language when controlling/flying.
If you work at a little local airfield and all you have is locals in the circuit, then go for it.. however, as soon as a foreigner calls on frequency, everyone should resort to a common language.
Yes, us Brits may be very poor when it comes to the number of us that speak another language fluently, but that is a terrible reason for you to do something that has contributed to peoples deaths in the past, and will do so in the future, if it continues.
Or are you advocating, as ComJam says tongue in cheek, that pilots learn the language of every country they fly to? Or perhaps we could have pilots that only ever fly to one or two countries, i.e. the ones they can speak the language of?!
However, Controlador, may I be the first to say that your written English and your obviously outstanding grasp of English Grammer and spelling, is possibly better than some of the English native speakers on here (me included). As far as your post is concerned, it is almost immaculately written and presented... well done