Everything was under delivered since the early 90s by Peter. I think het just gets off from the attention. Considering most of the projects were a financial success nonetheless, he probably saw this as a reason to keep doing it.
This really bit him in the end though with godus. A failed god game where he went to kickstarter for money. I guess releasing an under promised game when you ask for money before making it, promising all sorts of things and never delivering it is not really good PR.