he wanted to avoid having to later repurchase books purged from the shelf
I volunteer at our local library's used bookstore where some of our donations are withdrawals. I guess the obvious question is why would they be repurchased if they weren't circulating in the first place? What's also left out of TFS is that library circulation is often used as a metric for a branch's success, as market share is for internet startups (that don't necessarily generate profit). The excuse looks more like a fig leaf to promote the branch supervisor.
TFS does touch upon a more general discussion about what books the local branch should stock, or whether there even should be local branches in the day of Amazon and Netflix. Gaming circulation certainly doesn't help the cause for keeping local branches.
Finally, low circulation doesn't (or shouldn't) automatically point to withdrawal and books are withdrawn if they become 'damaged'. Typically issues develop with the bindings as book drops literally are, and they ain't a binding them like they used to. One of our group used to repair bindings to keep the books in circulation longer.