Sometimes you need hours from the best. You have a project and it needs to make a giant leap forward. You are very smart but also very busy. You need someone with deep, specific skill, someone who is experienced enough to get it right the first time. Perhaps even leave tests behind to make sure it stays finished.
Maybe, in fact, you need the people that wrote your framework.
While Agendaless focuses on big web projects, as Pyramid becomes more popular, we are increasingly called on to teleport into a project and help. Such tactical firepower is very attractive: you significantly increase quality (via deep experience) and speed up your delivery timeline. Both reduce project risk.