Perhaps because he, amongst others, consider the accused's greivances to be legitimate.
On reading of what people have posted there doesn't appear to be many who believe that the accused grievances weren't legitimate.
The issue is the way they have gone about airing their grievances with mass refusal to follow orders.
Incompetent leadership doesn't mean mutiny.
As indicated by others there is clearly a failure of leadership right through here.
It is not like you can accused people of cowardice because they were not refusing to fight or refusing to go to a hot zone.