Often when filing a new bug based on convoluted scenario, I get the same answers again and again from the PM and devs. Here are the reasons I have to keep pushing:
1. If you can think of it, your customers will think of it.
The usual first answer I get from PM/devs when I come up such a bug is “nobody would think about it”. I am far from the notion that I am the only “genius” that can think of something and nobody else would have the same idea. I just hope that I can think of enough things to cover 90% of the scenarios people can come up with.
2. Even if you can't think of a reason to do it, your customers will find one.
The second answer I get is usually “why would you want to do it?”. Well, I do it because I want to break the product and find bugs. :-) But people can find a way to use anything. In fact, there is a whole area in Microsoft, called Application Compatibility, that deals with applications that do exactly what the PM/devs don't want them to do in a way they never expected them to do it.
3. You customers will do things you never expect them to.
The third answer I get is “this is an Einstein scenario“. An Einstein scenario is a scenario that the PM expects no more than 2000 people (guestimate number) in the world to understand and use, thus it is somewhat lower priority.
In fact, in the Now and Here a single "Einstein" blog can have huge impact on what people do with your product and and how they use it. Lot of the modern Einsteins in the IT industry have great visibility, the ability to explain advanced things in simple terms and they post lot of source code samples. Morts and Elvises of the world read and learn and adopt Einstein techniques in their everyday work. So today's Einstein scenario might as well turn out to be tomorrow's Elvis and next month's Mort scenario.