Let us start things off by examining the reasoning behind the sale itself; as one could expect, it started out as a mildly humorous running gag about the mental lapses of wacky teachers. The problem is that when everything else turned into a grim exercise in despair, defeat, humiliation and loss, what started out as a gag turned into yet another thing to mourn. The question that we are forced to confront is "What exactly are we supposed to mourn this time?"
The first thing that we're probably supposed to mourn is the fact that people are mean-spirited idiots who won't support the school because people are mean-spirited idiots. Given how Batiuk seems to be rather averse to admitting that the reason that his Big Book of Cancer, Death, Doom, Despair, Heartache, Loss and Pain That Can Never End is that he made it impossible to cheer anyone on, the fact that Becky never once stopped to consider that there could be easier ways to raise money that stand a chance of actual success is something of a metaphor for Batiuk's artistic failings.
It's also a metaphor for the reason that isn't "Since people don't want me to keep plodding on doing the same doomed thing, they're mean and dumb and want me to fail so they can laugh at me" for why he keeps on failing. Years of watching him spinning his wheels tells me that he has no real idea of how normal people actually think. Simply put, the impulse that made him think that people want to be lectured about how they don't know what they need is the same one that made Harry Dinkle think that people actually wanted to buy a turkey door to door. It's also the same impulse that makes the people of Cancerview High get defensive when told that maybe they should do something that stands a chance of succeeding; somewhere in his heart of hearts, there is probably the extreme reluctance to admit that his critics are right.
We also have to deal with his obvious contempt for the younger generation. He started out as an arrogant prick English teacher (just like his avatar Les) and he still thinks of the kids of today in the same dim light. Why else would the reason that they fail that isn't stupidity and malice be the result of bumbling kids? It certainly isn't the school's fault for selling something no one would actually buy any more than the failure of "Lisa's Story" is his fault for telling a story no one could possibly be interested in.