Well I have, and even with RedHat's documentation and distribution, it's nothing short of a nightmare.
It took me a good part of a day to subscribe to RedHat's evaluation distribution, and configure maybe 2 out of the 7 or so daemons that are needed to get it to all hang together.... and this was starting from scratch with no idea how the open stack architecture hangs together. In fact, I'm still a bit fuzzy on the details.
Compare that with a vmware ESXi install. Within an hour or so, you're running linux in a VM.
For a contractor going into an organization trying to sell this, it's very very hard. Skilled people in Open stack are few. I can't easily set something up in Open Stack and then walk away, or the customer is in a lurch for support. The technology needs to be well supported and well understood with a community of techs.
At the moment, while I love open source and everything you can do with it, a typical organization would rather go with vmware due to it's ease of use and the number of techs that can manipulate it. Yes it costs a fortune, but it's worth paying because it's easier to support, and these enterprises have money for this.
Openstack is going to go great guns where in-house techs can deploy it for customers, and spend all the time in the world to learn it's ins and outs....but for everyone else it's too much hassle.
The comparisons with earlier version of Linux are apt. Just as enterprises don't want to roll their own Linux kernel, much less do enterprises want to hand configure their own cloud.
There will be a market for preconfigured & value-added open stack environments however. It's just too early to call yet.