It's also disrespectful to your opponents to make displays of arrogance (i.e. not trying). Taking a knee would be worse than scoring as it shows your opponents that you don't even have to try. Ten bucks says the parent was a mother. Actually, I don't have to bet, Sean Salisbury confirms it in the video.
Edit to add a story: I remember 20 years ago I was playing 10 year old traveling baseball. We got stomped by Vernon 35-5. Nobody complained to the other team. In fact, we were told we played like girls by our coaches. The next game we came out like a house on fire and beat our next opponent 8-3 (funny how you remember the bad losses, but not necessarily the win). The coach said that we finally played like men. Sad to think that if that happened today, the coach would immediately be fired.
Edit to add a story: I remember 20 years ago I was playing 10 year old traveling baseball. We got stomped by Vernon 35-5. Nobody complained to the other team. In fact, we were told we played like girls by our coaches. The next game we came out like a house on fire and beat our next opponent 8-3 (funny how you remember the bad losses, but not necessarily the win). The coach said that we finally played like men. Sad to think that if that happened today, the coach would immediately be fired.
10/14/15: The day I learned that convicted terrorists are treated with more human dignity than veterans.