During the Civil War the deadline was the prison’s “do-not-cross” line. If you crossed the deadline, you’d be shot dead right there.
Today you can cross almost any deadline and nothing fatal will ever happen to you.
I guess you can read this in two ways:
As there’s no direct punishment for sloppy planning, you can get by with promises that feed everybody’s wishful thinking, then take it easy and throw in a random apology once the truth inevitably hits.
Without the threat of the stick, you’ll need to sharpen your discipline and planning skills if you hope to get ahead.