That does not say “they should be banned if there isn’t” or, even closer to your interpretation, if nobody checks it out or anything to do with budgets. There are two separate ideas presented, not perfectly, but still pretty obviously. “I’m not interested in it but someone else might be, it shouldn’t be banned” and “library budgets are low, they aren’t just buying books for no reason”.
That does not say “they should be banned if there isn’t” or, even closer to your interpretation, if nobody checks it out or anything to do with budgets. There are two separate ideas presented, not perfectly, but still pretty obviously. “I’m not interested in it but someone else might be, it shouldn’t be banned” and “library budgets are low, they aren’t just buying books for no reason”.