"I still don’t see how not having enough contact with Arabic speaking people ( Locals as you put it, and I strongly disagree with putting the “ Locals” tang on everyone that speaks Arabic) Can be an acoustical"

Because for the vast majority of people (especially people over the age of say 25, like most expats are) its only really possible to learn a language by being forced to speak it ALL the time. That's how I learned Korean, I had to speak it ALL the time when I was there (and now that I don't live there I've forgotten virtually all of it).

If you never come into contact with anyone who speaks Arabic, you'll be awfully hard pressed to learn it.