I believe you could make an argument that those are the exact reason that the Crusades failed. Inept leadership, corruption, and lack of desire led to the failures more than anything else if I recall my history.
My understanding is that's not the case, but then again I'm learning not to place much faith in critics of western civilization whether the criticism is deserved (by western standards) or not.
The Crusades were an impossible task from what I've read.