Demise of APB. It was difficult to find anything comprehensive but the one sentence I did find was on this website. The relevant sentence is: "Also, the demise of the APB is often attributed to the failure to build a consensus among users and others." If you read the article, it's sort of counterintuitive - one the one hand, the APB required a supermajority to pass laws, but on the other hand, the article muses that there still was not enough assent.