I hear what you're saying here, but one of the ways we've been able to successfully preserve software was because, even though folks weren't supposed to keep this stuff around, they did anyway. Business goals rarely align with preservation efforts. While I do know that Microsoft does keep a vault of old software, production materials, etc (I believe they even have a position on staff for a Librarian, or at least they used to), for many other positions, that simply does not exist.