First of all, as I made clear, this wasn’t about you.
Second of all, these are little kids. Parents should not be looking to motivate them to achieve what they want them to achieve. If a kid wants to dog it at tryouts when they are 8, that’s fine. If they don’t like the team they get put on then they have learned a lesson. If a parent is constantly trying to motivate a small child than the kid will never learn how to be self-motivated. I am a teacher and a coach and I see this all the time. The kids whose parents allowed them to fail when they didn’t put in the effort are always more successful in ten long run than the kids whose parent always push them. My son did terrible on the first day of tryouts. On the second day he looked around and saw who the other kids were in his tryout slot, realized he was in the bottom group and proceeded to be the best player on the the ice, by a large margin, during that time slot. He stepped up during the third night and got put a level higher than I expected and was one of the bottom kids on his team. During the season he got shifted to D and worked his butt off to do a good job, than got shifted back to forward and did a great job. I never had to say a word to him to motivate him. Last week I caught him doing push-ups in his room and, when I asked him why he was doing them, he said he wanted to be stronger next season. He motivates himself and will be successful in life because of that.
That's short-sighted. Not all kids that fail try, or want to try, again, while almost every "successful" kid has failed at something, at one time.
For me, I'd much rather spend a few minutes getting a 6, 7 8 year old kid to understand the importance of the try-out/evaluation than explain to him why he's not playing with his friends, or on the select team, (or in your case tell him he sucks) for a year.