My child is pretty good and plays viola in the 7th grade orchestra. (Apparently viola is not that competitive- there are a million cellos and violins but only a few violas). He was named first chair of the 10 violas and invited to be in a special quartet, run by the conductor. (he is the only hearing impaired kid in the orchestra!).
The two violins and 1 cello were phenomenal- they were all Chinese-American, practiced at least 3 hours a day (their moms told me), and have played since age 4. My son is pretty good and was clearly the weakest player, although he got a lot better.
I can see what they are saying- orchestra in our area is super, super competitive and the kids/parents are not always very nice. My son learned a lot and would do it again BUT he hated being around the other kids and their parents, who were freakishly, bizarrely competitive and often jerks...