If your business is not in core tech, you are out of your competence to build your own multi-region cluster or a private cloud. It is a quite challenging task t

If your business is not in core tech, you are out of your competence to build your own multi-region cluster or a private cloud. It is a quite challenging task to start with, with unpredictable costs. Many HN readers do not understand this, as they always worked in core tech. And if you rely on systems integrators to do that, it will be quite expensive, and you are not sure if this particular integrator will be around in the next 30 years. (Amazon will probably be around, which is why AWS is popular, but sometimes public cloud is not an option at all). In this context, mainframes are quite competitive. Their costs are predictable (and comparable to, if not less than to private cloud offers from systems integrators), IBM will probably be around for long or at least acquired by somebody who will carry the support contracts (like Sun -> Oracle), and they will provide full technical support, again with predictable costs.