I don't think any of the contestants should feel bad about getting their singing judged. If they wanted to participate in the first time, they should be ready for what's next. Also, it's not like if the judges are being just mean on their judging, and I hope they know about music.
Also, something else I noticed is that the scores seems to be. Weird. If this is a grand prix, I'm guessing you're giving scores based on the place the people got and not on the feedback they got (Mario Kart style, first place gets 15 points no matter how fast he got to the end, etc.)
If you are doing it this way, then there's probably something wrong with the scores you applied...