My title is a quote from Gustave Holst (of "The Planets" fame). Some interviewer asked him what he thought of amateur orchestras. Aren't they just a sort of musical pollution? Above you see his answer. Of course he meant, "... worth doing even if badly.")
If you wouldn't do it unless you are really good at it, you must not love doing it, right? What you love is not the music, but being so damn good at playing the music.
I play second violin in an amateur orchestra (you see the back of my head in the lower left corner of this picture), and I am probably the worst player in the whole group. So I practice what I preach. Go though and do likewise!
Below is one of my favorite pieces of music played by The Portsmouth Sinfonia, an English group that took the Holstian principle into another dimension. Some Youtube wag attached it to the opening credits of 2001: A Space Odyssey.
(Hat-tip to Andrew Sullivan, who mistook this group for a high school orchestra. ... Oh, I see he corrected the mistake.)