I know exactly what I am talking about and have been working in this field longer than you, now in senior management. I was at your level, even running SCO Unix on Intel processors back close to 15 years ago, and up until just a few years ago SCO was the second leading worldwide *nix vendor behind Sun.
But since that time, IBM decided to (likely illegally, case is in US Federal court now) port Unix features to Linux and give them away for free, and since that time we've seen an explosion of Linux worldwide since the foreign governments could now obtain this software completely without cost, at the expense of the US Unix vendors. Just because you weren't aware, doesn't mean it wasn't happening.
Quite interesting the chart you show is for 2000. The computing world has changed a lot since then. I still stand by my previous post. The actual cost of the O/S has nothing to do with its use and your post contains nothing to refute that. Given your credentials, and I have no reason to doubt them, you should know that.
Do you have an updated chart? What about one with a breakdown of which O/S is dominant on x86 platforms? As I said before, in 2000 I also thought Sun would continue to dominate the market for a very long time. They haven't. Why? Blaming it on the various Linux/BSD packages being free sounds good in a sound-bite but there are much deeper reasons for it.