> Well, now it'll take them 5 minutes to rewrite their code to work around your change

You misunderstand. It will take them 2 years to retrain 5000 people on the new process across hundreds of locations. In some fields, whole new college-level certifications courses will have to be created.

In my specific experience it’s just a few dozen (maybe 100) people doing the manual process on top of our software and it takes weeks for everyone to get used to any significant change.

We still have people using pages that we deprecated a year ago. Nobody can figure out who they are or what they’re missing on the new pages we built

That will be after it broke, which costs money

Also: no