Although salutations may not be standard phraseology, they may be argued to enhance safety of the air - with minimal cluttering of airwaves - by focussing the controllers' and fellow airspace users' minds that a new aircraft has come on frequency, or one is about to leave. That in addition to plain curteousy is one of the reasons I believe it should stay in use.
Your reaction to hear Allah on the airwaves is a bit jumpy it would appear.