I think it depends on what you are and what your idea is. If you're a developer and it's a product you can have a prototype built for in a small amount of time

I think it depends on what you are and what your idea is. If you're a developer and it's a product you can have a prototype built for in a small amount of time (say 1 or 2 weeks) then just fucking do it but obviously if you're a business development person who needs to contract out you have to approach it differently. However the way people articulate ideas matters a lot, so unless you're 100% confident in your ability to articulate ideas then I can see this being the cause of missed opportunities. If I have an idea I believe will work well, I build it, if it fails it fails, asking people isn't something I'd base the choice to make or not make something on just because the people I know is limited, there is always someone out there who will use your product (even if it's just you) it's a big gamble to assume those you asked is representative of that group.