The public doesn't know about good security work, unfortunately sometimes the police doesn't either. In most security work your objective isn't too win, it's not to loose.
This video[0] is a perfect example. It's was taken during some parade in Northern Ireland. The rioters are trying to break through police lines and, well, generally riot. Observe how the police at the top of the screen at 0:25 looses his temper and tries to go after the person in the blue hoodie. This would be an example of trying to win. He's hitting you, you want to hit him back. The problem is that you are quickly going to loose control over the situation. Worst case scenario individual officers find themselves surrounded, the line is broken, everything turns pear-shaped. This would be loosing. In this case the officer behind him quickly pulls him back in the line and talks him down. In the short term you haven't won, but more importantly you haven't lost.
Also look at the crowds reaction at 0:30 as they become even more aggressive. It's boring to fight someone who doesn't fight back. As a bonus, also look at 1:10 how the rioters form a "human chain" to not get grabbed by the police. Each person is holding the one in front of him to be able to pull him back.
[0] http://www.youtube.com/watch?v=YqfB3jlih50