Agree, good post. Emotions are good. You want kids who care. You want them to hate making outs. Don't coach that out of them. Praise their competitiveness, but of course, teach them that managing their emotions will help them avoid those outs that they hate so much. If you label the emotions as disrespectful and selfish, they might stop caring in order to avoid the punishment of those labels and lectures. Then you have a bigger problem.
Emotions, by themselves, aren't "disrespectful and selfish", but actions resulting from them can be. Showing up an opposing player or umpire, a lack of hustle, and bad behavior towards team mates can all qualify.