I recently subscribed to the Joy of Code blog which I am liking a lot, and this post struck a chord with me. The thrust of the article is that software vendors shouldn't waste time tarting up their interfaces: what we need is standard, functional interfaces. While I agree that these "flashy" UIs can be very frustrating, or even unusable, I enjoy seeing an app go beyond the ordinary and try something different. Arguably the most successful company at not following the "Microsoft way" is of course Microsoft:
To answer the rhetorical question, I guess development teams at virus scanner companies have pretty much done the hard stuff, so have time to work on differentiating themselves from the competitors. Still if you're just trying to get something done, a plain, simple, intuitive UI is what you need.