This "apocalypse" has already happened to neocodex at least once before. Site activity dropped to only the same few dozen people and there were only a handful of programs. That definitely didn't stop me from joining (hint: it was the solid small community that made me participate in the first place).
As for money, this site originally didn't have subscriptions. The owner, Hydrogen, didn't care that he was paying out of pocket for one of his projects and a small old community. Subscriptions only happened because users were begging for it. They wanted the benefits that established members got from Abrosia and offered to pay for it. NC Card sales don't matter too much. It brings in money but it isn't needed to keep the site up. If neopets shuts down for good, we will adapt and live on with the members that enjoy the community.