Your logic is perfectly reasonable and sound, and it took me many years of working for Big Corp (TM) to understand that is simply not how a big corporation thinks.
Once they have a revenue stream, anything that diminishes it is a "loss", even if that revenue stream was kind of fake or invented anyway.
The massive company I worked for was making millions per week from something that was accidental and they shouldn't have been. But it went on for so long, they got so attached to it (those millions looked great on year-end reports) that soon any talk of "fixing" the problem was referred to as a "revenue loss" and it was completely unacceptable to the business, unless your proposed change kept the revenue.