In fact, an EPO system is a single point of failure... And, whether or not you need an EPO in your center is wholly up to you, and how you design your center. As mentioned at a recent seminar I went to: "If you do not need to install non-plenum rated cable below a floor, and you require boxes under the floor to be secured, and you do not state NFPA 75 as your standard, then you do not need an EPO as defined by NEC 645." Only if you want exceptions granted in 645 ("Information Technology Equipment"), should you have to install an EPO. EPO = SPOF = bad. We all know this.
If they can be avoided, why do we put up with them? Do we really want our colo in downtown San Francisco bad enough to take the risk of having a single point of failure? How can we, as engineers, ask questions about how many generators, how much fuel, and yet take for granted that there is one button on the wall that makes it all turn off? Is it simply that having colo in the middle of the city is so convenient that it overrides the increased cost and the reduced redundancy that are necessitated by that location?
You forgot the default "Single Point of Failure" in anything..
HUMANS.
Tuc/TBOH