It's a fail-in-place data center. If a hard disk fails, you don't do anything. They used to replace telephony equipment all the time too, now it's just a locked room in a building. This is pushing data centers to be more hands-off.
That kind of thing eats directly into the ROI for a datacenter. I doubt it competes with a static building with a bunch of solar panels on top.
In theory you'd only leave it down there for three years anyway before everything in it is worth zero, at least to the IRS.