Their usage of “any” is clearly different than yours: “any [and all]” versus “any [at all]”.

Their usage is improper. If that was their intention, it should have read “every area”.

Their usage is fine, and I couldn’t have imagined interpreting it any other way until I saw your misunderstanding. But if you’re more interested in correcting arbitrary grammar rules than gaining a better understanding of the conversation you joined, that’s my cue to drop it and go do something better with my time.

It's not my misunderstanding, it's their inability to communicate clearly. I already explained why it's wrong so there's nothing to understand.