Guest, I know what you mean.

If you are among artists and performers, it doesn't take long before you detect professional jealousy in some people. In fact, it's so common and so recognizable that "professional jealousy" is a standard phrase.

Is the artist who exhibits professional jealousy a mediocre artist? Probably. Is s/he lacking in shrewdness? Certainly. If the act being ridiculed is a good one, s/he will be judged stupid, and if it's not that good, s/he will be judged a bully. Either way it won't add to the good atmosphere of the event.