Like you, I appreciate your point and agree with it to a point - i agree that they must have that desire (and if they don't they're in the wrong job frankly) but, if they are struggling wether it be due to a lack of confidence (i can't pretend to know the level of pressure they are under), or...
But as the players regularly say, the atmosphere spurs them on. It's not just one or the other, both have to help. If the team are struggling, it's up to us to give them a lift. Likewise they'll pay us back by pushing on and justifying the noise.