In doing so, they have demonstrated that Egyptian Soldiers are righteous, professional soldiers. They are not cowardly killers and beaters of unarmed civilians.
The sole valid reason for an army to exist is to protect the nation from invasion*.
Their role, irrational and problematic though it is when viewed objectively, is to try deter, if necessary with lethal force, any armed invaders who try to occupy their country.
That is the central role of an army: protection of their nation, its people, territory and values.
The real, professional soldier is not there to kill unarmed civilians of their own nationality.
This is why the Green Party has this policy (PD306): All serving personnel will be required to sign a pledge that they will not obey any order which would entail any breach of international law. In particular they will be able to disobey any order that required them to fire on unarmed civilians of their own or any other country.
Maybe this is a good day to raise this question:
Will the British Army make a solemn oath that they will never use force against non-violent British civilians?
*OK, primary purpose. Commenters are welcome to enter other uses, like, UN peacekeeping missions.