Israel phased the Galil be cause we (USA) were giving them M-16s. Why build great rifles when someone wants to give you ok rifles for free?
As far as accuracy and reliability, it uses the Kalashnikov style gas/feed system (as reliable as it gets). In addition, the rifle weighs around ten pounds and fires a lighter bullet than the AK making it more controllable.
"9mm has a very long history of being a pointy little bullet moving quickly" --Sevens