@Mark Hahn
Of course you're correct: a bit of skull-sweat with our think-caps on and this can be done.
The problem is that most data centre managers these days are looking for a "turn-key" solution from a single source, as it's less work for them and easier to focus blame. IBM has 70+ years making money from being a "blame magnet" for management teams ("It's not my fault, IBM said to do it!") by delivering these type of "turn-key" solutions.
Remember, your average corporate Director or Vice-President level executive has about the same technical savvy as Paris Hilton - not too different than the BOfH's manager. Submitting a request to the Budget Committee to "...triple Data Centre capacity without buying a new building - $15M..." makes them a Hero both for saving on real-estate AND keeping the request to a single line-item.
All in all, however, IBM does a pretty decent job of delivering what they promise. You can certainly do much worse than buying an IBM installation.
Paris, because she can get a job as Director of Data Centre Operations at most companies...