Some time ago, toward the end of an article about attending the San Francisco Symphony, I suggested that maybe the audience looked very serious because the musicians looked very serious, and maybe the musicians could look cheerier.
Well, if you're following Drew McManus's blog Adaptistration, you'll understand why the musicians might not look very cheery. Read, especially, The Money Drug. Read the NY Times article from several years ago about the ergonomic viola and the risks orchestra musicians run. Lousy working conditions, lack of job satisfaction, feeling that they have no control over their professional lives, repetitive stress injuries - I expect I wouldn't be be very happy either. My experience of performing is strictly as a student and amateur: for the love of it and getting an enormous amount of satisfaction out of what I do.
It's not hard to read between the lines and figure out things symphonies and other performing organizations could do to improve working conditions and improve musicians' job satisfaction. Managers, what are you waiting for?