1. Even software with no "accidental" complexity is necessarily complex (in fact, that's why it's useful).
2. If the manifesto's point is that we should stop over-complicating things, then wouldn't it better to first examine whether, and if so why, things are overcomplicated now, given that the previous generation also went on a crusade to abolish (over)complication? If the point is to declare "don't overcomplicate!" then, if you believe things are overcomplicated now, why is that declaration useful if it's clearly not effective?