The reason those companies are still running the old versions is because even if they're out of support, they're known quantities. Implementing new versions will require development and testing to put in to place along with the possibility of additional upgrades (OS, other apps/libraries, etc.). Unless you have resources to handle that aspect in addition to any of your actual business, you're going to want to stay on a version for as long as possible instead of being on the upgrade treadmill that Microsoft/IBM/Oracle try to place you on.