My company doesn't require this, but I also don't understand in any way how adding copyright boilerplate to each source file has anything to do with the writer's integrity. Are the people in the GNU foundation lacking in integrity, since they have this policy?

Placing copyright notices on things you don't have a copyright on amounts to making a false claim that they are not only copyrightable but that you own the copyright, hoping to intimidate other people out of exercising their legal rights. Lying in order to intimidate people, particularly to intimidate them into paying you, is not only dishonest but contemptible. It's no different from the mugger who says he owns the Golden Gate Bridge and demands $10 from you to cross it.

The GNU foundation, whatever its failings, does not have a policy of claiming copyright on blank lines.

I thought your comentarii was referring to the practice of adding copyright notices to files in general. Specifically adding a copyright notice to an otherwise empty file is indeed scummy.