Many people and companies are "way behind the times" so to speak. Not only that, but in the case of software, the original programmers who developed the applications have likely long since left and the "monkeys" in charge don't know how to do anything more than apply patches to the original software (then call them "updates" or "upgrades" or even "new versions"). As for people, some will actually use the META keywords tag to power an internal site search. I know Stephen Chapman (aka "felgall" on the SitePoint forums) actually does this.
it's useful information about of Meta tags for website optimization but i am using content relevancy because if use follow this then you get lost if better result...