Greencardman said:The main reason is that the designers don't have time to learn OS X and to figure out how to do things all over again...
This is true but it's also important for any creative to keep up with technical developments especially when the cutting edge becomes commonplace... I didn't force through an OS X transition at work until I had about a year of messing with it at home and had researched a number of issues. In fact, it was that experimenting that lead me to this very forum.
While it all comes out of my own time, I also see it as an investment in my career and it pays off. I would hate to be still wedded to OS9, a position I was in 2 years ago... InDesign is something I intend to spend a lot of time with over the next few months at home before trying to do a day's work with it.