As we looked to the mainframe for "deterministic certainty," Anthropic handed the AI a crowbar. IBM’s 13% swan dive—its worst day since 2000—reveals a massive market bet: we’d rather have a fast, cheap, "vibe-coded" migration to the cloud than a slow, guaranteed life in a COBOL vault. Are we witnessing the "Probabilistic Purgatory" of our last stable systems, or is the 1970s "Adult" finally being sent to a retirement home?