Wouldnt TCO be less with open source technologies? More tech savy employees would be more valuable to businesses in the long run I would think. Am I wrong?
Have you ever tried to get someone who is technologically illiterate to change to a new application? The easier you make it, and the more familiar platforms you use, the easier training becomes.

Easier training=cheaper training and a more efficient operation.

In many cases the applications costs between different platforms is negligible, and compatability and ease of use trumps all.

A more tech savy IT person is great. A tech savy graphic artist is still a graphic artist at the core. The arts training and ablities are what matters, and you tailor the platform and app suite around the population, not vice cersa.