Why are ideas cheap?
Anybody competent always has far more worthwhile ideas than has while to work on them. Nobody else competent has time to work on them either. Good ideas protect themselves: only the best recognize the best ideas. It takes a great deal of hard work to make any idea valuable. The best ideas just evoke the most work. Mentioning a spare idea, though, might spark another one good enough to make you (or them) drop what you’re doing to pursue it.
There are reasons why more happens where information is shared freely.