Interesting theory, but I think something else is happening here.
If you have a bunch of people trying to solve a problem, the game is implicitly defined as "propose the best solution." After the first proposal, the game changes to "improve on the best solution so far."
This is something to keep in mind during interviews [1] for people on both sides of the table. If a candidate is silent for too long, propose a bad idea and ask them to improve on it. That gets them talking out loud, and you get more info to go on. If you're a candidate, you can start with a bad (yet probably obvious) solution and explain why it's bad. In the process of talking it through, you'll likely think of a better solution.
[1] The algorithm/coding one-big-question-over-45-minutes style of interviews commonly conducted by large software companies.