To be fair, a lot of breakthroughs happen by people outside the field in question applying new ways of thinking to that field.

Sure, these people can be kind of annoying, but I think we lose more than we gain by discouraging cross-pollination between fields of science.

Definitely; I was thinking that earlier while reading this post. On the one hand, you have newcomers who might have an answer no one thought would work, but on the other hand experience nets wisdom that often is more accurate than the newcomer's logic.

It is a tough call to make between what's happened and what's possible.

Douglas Crockford should learn from you and use the term cross-pollination instead of promiscuity. That would have saved him a lot of trouble