Is a certain level of demonstrated proficiency in English not a regulatory requirement
Yes
Why would you not attend an English exam if your employer instructs you to?
The actual quote is
Or that you can be fined 4,5 MILLION € for not attending an english exam or similar trifle things?
I believe the point that Daermon ATC is making relates to a Spanish law which makes it illegal to refuse to "cooperate" in ATC.
The problem that has arise is that they law seems to be very vague on specifics.
Hence the comment comparing the requirement to be proficient in English to
any minor issue which suddenly finds the full force of the law behind it.