Every person has different ideas about how Bach should be played... There are three basic schools of though.
1. Bach was written for harpsichord, and should only be played on harpsichord. No pianist can or should play Bach, because they don't have the right instrument... Would you play a piano concerto on a violin?
2. It is OK to play Bach on a piano, it should just be tastefully done. That means doing your best to keep the piece very baroque by using terraced dynamics (only forte and piano) and by keeping your phrasing, articulation, ect. at a minium.
3. Not only is it OK to play Bach on a piano, but you should play Bach with the full resources of the instrument. This means using lots of dynamics, influding the in-between ones, and adding phrasing and articulation. Some people feel that this keeps Bach from becoming a technical study.
Now, from what you said, I would say you play Bach like option No. 3, and the judge was looking for something closer to No. 2. This doesn't mean that he's right, and you are wrong. This just means that you disagree. It is my personal opinion that you should look at each piece, and decide how to play it. When I play Bach's French Suites, I play them closer to No. 3. Many of his WTC preludes and fugues I play closer to No. 2. There really isn't any way you are supposed to play Bach. It's all a matter of personal opinion. All you have to do is go out there and play like this is the only way, because it's your way. If you can play with a very convincing, confident attitude, that might make the judge see the whole of what you are doing!
I hope this answers your question!
Love,
Sarah