Thanks for this. I agree, there seems to be some sort of resistance to building and maintaining a CoLo infrastructure. In reality, it is not too difficult. As I mentioned above, spare parts on the shelve with the CoLo "remote hands" support and a good monitoring system can lessen the impact of almost any catastrophic issue.
For the record, I have built (and currently maintain) a number of CoLo deployments. Our systems have been running for +10 years with very little failure of either drives or PSUs. In fact, our PSU failure rate is probably 1 every 3-4 years, and we probably loose a couple of drives per year. All in all, the systems are very reliable.