It's not about winning or losing; it's about competition and respect. Everyone who takes the field should be playing to win; everyone who takes the field should be prepared to accept a loss and even a blistering as part of the natural order of competition.
When it comes to goals, though--and I'm not talking about the ones with the nets--there's a big difference between having the goal of playing hard, winning decisively, and improving the confidence and overall ability of your team vs. having the goal of seeing just how high you can drive the score.
Sometimes it happens regardless...after all, it's the defenders' job to figure out how to keep the ball out of the net, not the attackers', and if your second and third string are still scoring, well, they've probably waited patiently for the opportunity so it's not fair to them to tell them they can't. But if you've got kids sitting on the bench and starters still on the field just because you're not satisfied with how high the score is, you might want to re-visit your overall goals for your team.
