At some point in time the original person isn't available anymore and whole setup will have troubles because of upgrades of the basis (e.g. Excel) or just performance problems. They are even consulting companies specialize in optimizing or migrate to new Excel version for such kind of applications.
The corporate IT have to pick up the users early to help them to solve their current problem or help them to be more efficient with IT. If nobody helps they will develop their own solution which the knowledge/tools the have.
I say this not to disparage those apps (though they were often horrifying to us as devs) but to point out that huge portions of your average large business probably run on stuff like that.
Any earlier commenter said Enterprise values process over outcome. It is true at the macro level but at the micro level bosses need to make decisions or your new work will receive no credit from above and will be used against you when it fails.