The Deaccessioning Blog notes "at least three other reasons why anti-deaccessionists are wrong."
Relatedly, The Art Newspaper has "identified over 20 important shows that have been axed (or, in a few cases, postponed) later this year or in 2010," which, they add, "almost certainly represents the tip of the iceberg."
It's a question of opportunity cost. As economist Bruno Frey has said, "at a (real) rate of interest of 5 percent per year for instance, a painting held by a museum and worth one million Euros means a steady flow of income of 50,000 Euros forgone each year, i.e. which could have been used in a different way. Thus, the painting under consideration could be 'transformed' into a permanent flow of 50,000 Euros, which could be spent on" -- well, lots of things, including not axing important shows.
One example The Art Newspaper mentions is a Gorky retrospective that had been scheduled for LACMA in June 2010, but has now been canceled.
So maybe it's more important to have that 220th Eakins sitting in storage year after year than it is to have that Gorky show.
But maybe it isn't.