For how many years has dual-language ATC existed and how many accidents can you attribute to?
And what is the percentage increase in air traffic movements in busy Terminal Environments? More jets in the sky evey day. Once backwater regional airports getting more and more commercial traffic, thanks to the advent of LCCs. So the number of acceptable incidents " provided the frequency remains low" suddenly may have a few more players joining the game (a little sensationalist I know).
Anyway, in 10-15 years it'll all be automated. All the little computers talking to each other. You reckon Air France's computers will communicate in French? And then go on strike? (sorry, cheap shot)