Some engineers prefer to quit employer than change technology. For example someone called Moe Taxes who says I don't feel like I have enough control over the product when I use Microsoft programming environments. [Source: Slashdot, but the discussion quickly gets off the point.]
Rocky Lhotka rightly points out that an engineer cannot grow professionally while refusing to learn new technologies. It is also true that new technologies may call upon the engineer to relinquish some aspects of control, and some engineers find this scary. On the other hand, Sahil Malik says that he'd rather specialize and be an expert in what he's already good at.
So there is an interesting relationship between technology adoption at the organization level, and technology adoption at the individual level. Sometimes the affiliation between an engineer and a given technology is stronger than the alliance with the employer. The pursuit of excellence can sometimes inhibit innovation, both for individuals and organizations. But that isn't a reason to discourage the pursuit of excellence.
Looking at the problem from the other end, I heard recently of an organization that had decided to adopt SAP software, but then got stuck because it couldn't find anyone with exactly the right combination of specialist industry knowledge and SAP skills. (This was not surprising because they were the first SAP user in this particular sector.) Again this can be seen as a control issue - the organization aspiring for a perfect SAP implementation, while being distrustful of SAP specialists from outside.