Many organisations require 24x7 mission critical support - e.g. telco's covering "blue light" services. Even though our systems are designed to support these critical services, things do go wrong - the usual problem was between the chair and the keyboard, but now days theft of copper wire is the most consuming man made problem.
I and my "buck stop support" team would rather be on call and able to resolve problems remotely, than have to work shifts over a 7 day week........