Cloudslop doesn't provide high availability the way high-availability platforms provide high availability. IBM is still doing brisk mainframe business. You won't find mainframes in many data centers because you need nearly a data center's worth of hardware to provide the volume and availability of one mainframe, and that can fit in one cabinet. (Mainframes also benefited from VLSI; new ones aren't dinosaurs that require three-phase power, their own floor of a building, and their own aircon infra.)