Ask HN: Is the private cloud the worst documented thing?

Over the past few weeks I've been sampling a lot of hypervisors for running private cloud instances with decent support for control via API.

The question comes to mind: could it be that hypervisors and private cloud software is actually the worst documented thing these days?

I did sample installations and multi-node setups at my office rack with these:

- VMware ESXi - XenServer - Debian + Proxmox - Debian + OpenNebula - Debian + OpenStack

Why these? Well, mainly due to the fact that a key requirement for private clouds is control via API and API tooling is kind of sparse apart from these contenders.

Are my contenders just not used that much in real world use cases, or is it just the fact that the missing documentation/non-public knowledge results in DevOps nice consulting invoices?