How are low cost concerts and museums funded? Are donors sufficient? Is it the low cost of living and resulting reduction in staff costs? Is it sustainable in the long run?
Actually, "excellent" is the wrong adjective. "Competent" is all that is necessary. However, the non-profit world is often beset with incompetent employees at all levels, from your average worker all the way up to the top directors (well, usually B begets A). There is a problem in the field of people interpreting "we are a non-profit" as "we are a charity in all aspects, including hiring". There is definitely a feeling that only "heartless" (i.e. for-profit) companies worry about productivity.
Let's put it this way: if'n you ever had the notion to lie on your resume to get a job, look first to the non-profit world[1]. I've seen several instances at several locations of people with long-standing careers where they STILL aren't competent at the skills they lied about having on their resume when they got hired.
[1] that should be read as an indictment of the field, not a recommendation for lying on your resume.