So the CEO of an important customer of ours (no, I won't tell you who it is) claims to be, um, "very technical" and therefore keeps his own Windows domain and refuses to be part of the corporate forest. Go ahead, take a moment to express your astonishment; it took me about a full minute to recover my composure, too! Well, their IT is re-engineering part of the network and now has to, yet once again, figure out how to incorporate the non-standard and unmanaged "personal network" of this particular maverick.
This is a load of nonsense, as I'm sure you'll agree. No matter how I spin it mentally, I simply can't envision even a single business justification for this CEO to exempt himself from policies that everyone else is required to follow. He apparently fails to realize that his choice sends a clear message saying, in effect, "The policies suck and I know it." His behavior probably demoralizes the entire IT staff and communicates to them that he doesn't trust them and that they have no value.
Also, and probably even more important, his stance arguably increases costs to the organization. Just consider the ongoing extra (costly) work required for building the additional design, testing, troubleshooting, and support necessary to accomodate his silly whims. No worthy CEO -- one concerned with shareholder value and organizational performance -- would willingly do this. I know one company whose products I now will never buy.