It seems to me that at least according to that article, it also depends on what you consider to be "exciting". If you consider Twitter exciting, OK - maybe I am too old to be excited by that (been there done that with the social networking, not that excited anymore). Targeting young people might work best for other young people. But what about startups that target old people? Newspapers are reporting about the aging of society all the time, but Web 2.0 doesn't really seem to account for it yet?

Personally, I would consider a startup targeting old people exciting, and maybe older founders would have an advantage there.