Every IT person alive has fixed something in the "wrong" way, a way that wasn't scalable, secure, or otherwise proper, but a way that worked. It may have been intended to be temporary, but time passes and it becomes permanent. Over time, such fixes are often applied to problems caused by previous bad fixes. But they work, tenuously, for now.
This sort of activity takes place constantly, and indeed, it might not become a huge problem for quite some time. But there will be a point when there's no more room for kludges and poor fixes.
Simply put, when you've attached enough Band-Aids to the corpus that it's more bandage than not, isn't it time to start over?
It's one thing to understand that such problems exist (and always will, to some degree) within a corporate IT infrastructure; it's quite another when the problem is extreme and affects products your company produces, sells, and supports.