It's incredibly myopic to say that an hour of downtime equals an hour of lost revenue. When my favorite takeout place has busy phone lines, I wait 5 minutes an

It's incredibly myopic to say that an hour of downtime equals an hour of lost revenue. When my favorite takeout place has busy phone lines, I wait 5 minutes and then call back. I wanted to search for something during the downtime, and I didn't go to Yahoo--I waited. They definitely lost revenue, but it is a ridiculous, baseless claim that everyone went somewhere else during the downtime. You have absolutely no data to make any such claim. Furthermore, your calculated cost of an engineer's time is simplistic and inaccurate. It doesn't count the lost revenues from delaying the release of their work, and the reduced value of that money by gaining a lower time value for it (getting money earlier means more time to multiply it through investments and reinvestments). And, even worse, you are comparing the DAILY costs of developer time (which you grossly underestimated) to something that happens, maybe, once or twice per decade. It could cost them many millions--maybe even hundreds of millions or more--per year to implement such a policy. That's why these mistakes happen--it is cheaper to fix the rare screw-up than to waste too much time checking everything, except for very few circumstances.