Many nations see it as a key leverage point for economic advancement, a way to level the playing field, to design more effectively and manufacture more quickly, at new cost points. There are, and I don't want to discount them, especially the technology barriers. On the other hand, when the supporting technologies converge, the rate of adoption can be profound. The Internet is a perfect example. Nevertheless, there is inertia that must be overcome.
Companies have a lot invested in legacy data and complex drawing centric organizational processes.
Adoption of technology across large organizations, involving many functions and many people takes time. There are education issues, people issues, and process issues. Tuning the organizational engine while it's running is a slow and difficult process. One of the big barriers in the past was sharing the model. If an individual had to create a hardcopy drawing to communicate with someone else, you lost much of the benefit of the model as a driver of a model-centric process.