Non- central !!!

the museums sector is both politically non-central and, quite commonly, a semi-detached part of the overall political system, free to operate in its own way as long as this does not negatively impinge on the larger political and ideological expectations and requirements of national, regional and local governments.

What does non-central mean in that sentence?

And when it is a semi-detached part of the overall political system, why is it free to operate in its own way?