Not exactly something happened recently. Just today I come across something that reminds me about it.
Say, you'd done some development for project X that works for specific company. The project already goes live and their users are using it.
Since this is a huge system that spent many man-year to create, your boss think "why don't we generalize the project and sell it for other companies so we can generate more profit?"
So the boss sent out salespeople and a few interested companies show up. After gathering requirements, the boss need to quote the man-days to the potential customers, and hold meeting with the team lead to discuss. The team lead take a good look of the requirement list and draft the function point breakdowns for the meeting.
When going through the list of function points breakdown, one feature Z raised the boss's attention.
This ought to be something simple, why do we need over 60 man-days to implement it?
This is because to implement it, we have to build the prerequisite functons U, V, W, X and Y first. And to build function W and X we need to modify the already complex calculation function S and T which we'll need extensive test before going live. Honestly speaking I'd feel more comfortable to quote 180 man-days but .
I've told you to design it to be extensible. Why haven't you do that?
You're the one who told me "We have tight deadline. The number one priority is to put this thing to live. Don't spend time to meddle around features, specifically V, W X and Y, that the users don't need.", so ...
Don't try to argue your fault away. I don't care how you do it, but I want to see it be done ASAP. You have 45 days to do it.
Okay, so with a lot of detail smeared away, the essence is still there: Why do bosses think that features that they told us not to do, and have never assigned time to, would be automagically appear?
Similar things happens more than once, on more than one companies.