What IBM didn't realize was that the joke was on them. They ended up with an operating system that was generally considered to be difficult to install and support, and was almost universally considered to be inferior to the product developed by the tiny team of 45 at Microsoft. When a software project is running late, the last thing you want to do is add more people to the team. More often than not, this will only result in even more slippage. Like dousing a fire with gasoline, this makes matters worse, much worse.
More fire requires more gasoline, and thus begins a regenerative cycle which ends in disaster.
Observe that for the programmer, as for the chef, the urgency of the patron may govern the scheduled completion of the task, but it cannot govern the actual completion. An omelette, promised in two minutes, may appear to be progressing nicely. But when it has not set in two minutes, the customer has two choices - wait or eat it raw. Software customers have had the same choices. The result is often an omelette nothing can save - burned in one part, raw in another.