[infamouscow]

Putting the braindead straw man aside:

The systems built were designed for a business that evolved, and the assumptions and constraints changed in a way that sometimes requires redoing things. This can be as simple as an assumption about how sales will be acquiring new clients, and how those new clients affect overall system scalability. If there's a long pipeline of feature requests and sales supersedes product managers on roadmaps, doing the necessary work to scale the systems is going to be deprioritized to a point where anything other than downtime is acceptable from a business standpoint. Sales are made on features being built, not on an impending doom that has yet to happen. This extends to other aspects of systems, like security.