The problem in the Arab world is that their culture has both a strong tribal streak and is very much stratified by a nearly fixed class structure based on family ties. What this means militarily is that the leadership (officers) are drawn from upper class families based on their social and economic status rather than ability. The rank and file are from the lower classes, have little or no social mobility, and are unmotivated to put any extra effort into their performance since they know they can't move up in status.
This creates a huge gulf between the enlisted and officers and a military populated by unmotivated soldiers often led by incompetent and aloof officers.
Against Israel where they have a very Western societal model with greater social equality and mobility, the Arabs simply don't stand a chance in combat.