There's also the "That Won't Work" person's sibling: the "I Don't See a Use Case" person. In my experience, "I Don't See a Use Case" people require more sophisticated tactics if you actually want to get something done while they're around, not least of all because they move the game to a harder field: "that won't work" at least states a fact, whereas "I don't see" moves us firmly into "belief" territory, and "a Use Case" invites us into the trap of dreaming up our own strawmen for them to tear down one by one.
I wonder if they started out as "That Won't Work" people, but evolved better defenses?
When I hear this phrase, I think of GNOME. Can't count how many times the developers of GNOME have knocked back perfectly sensible pull requests or feature proposals on this basis.
...often only to implement the exact same feature later when it appeared to be their own idea instead of coming from the outside.
It's just an excuse to be insular and shut anything down, which is their default response to anything coming from the outside.
I promise I’m actually curious and not trying to be difficult: is this the same as asking “what problem does this solve” or something different? I’d love a concrete example but I know that might be hard without using a real topic.
I think it could be the same but it doesn't have to be. "What problem does this solve" is a bit more generous as at least, on the face of it, it may offer an opportunity to provide an answer that will be received in good faith.
But I think this is less about specific phrases one might need to be careful not to say, and more about the kinds of default attitudes that can turn into ongoing impediments to the free flow of ideas. It's definitely possible ask "what problem does this solve" without becoming the "What Problem Does This Solve Person", and the same goes for the other phrases too.
The phrasing is less important than the attitude - if you're actually open to a use case to justify the request, I wouldn't care how you asked. If you want me to put a round in the chamber so you can shoot my idea down, I think I'll keep my user stories to myself.
I wonder if they started out as "That Won't Work" people, but evolved better defenses?