"What can account for this peculiar set of rules, which seem to prevent museums ... to take actions that are not only consistent with, but would often seem otherwise mandated by their charitable purposes?"

At the Faculty Lounge, Brian Frye has some thoughts inspired by the fact that most museums can only show 2-4% of their collection at any given time.  And he teases an upcoming article tentatively titled "Deaccessioning Norms are Unethical."  I love it already.