Earlier quoted context omitted.
Why not just not answer your phone while on vacation?
Presumably because of pressure from superiors. If they know you're in cell range and ignoring them, they'll be pissy. If you're simply unable to receive communications, that's just the way it is. It shouldn't be like that, but it is.
Frankly, I'd be "pissy" if my superiors tried calling me when I'm on holiday and I would have no qualms informing them of that fact.
But then I'm not American.