I'd rather trust someone that has worked as a judge at the highest level in their own national court, rather than academics that are long on theory but have never tried a case.
The European Courts aren't really a higher courts than the national high courts, just ask the German one. Which, yes, does include academics and even civil servants with extensive background in law. And unlike say in America, the academic qualification you need to be a judge is higher than the one you need to be a lawyer, in the first place: Whether your professional choice then is to become a judge or something else changes nothing about your qualification.
They seem to think they are higher courts, given that people can appeal to them after exhausting the process in their own country.
It seems strange that people can become judges without actually practising the law or working as a judge in a lower court first. If I was being operated on, I'd want a surgeon that has operated before, not an academic expert on surgery.