LOA is a big part of the "should I stay or should I go" thought process. If you're not a boarding school type of family, it's probably the biggest driver for staying in if a decent job is calling.Most postings abroad (bar Cyprus and Canada) have local hirings rather than pads quarters. They have tax free purchases including booze, fags and cars.
They are likely to be eligible for CEA or any international schools for their kids.
The quality of life tends to better as well.
I doubt anyone will leave over LOA.