To Show & Tell or to Hide & Keep?

The idea-producers I've met so far, divide into 2 groups:
the show & tellers,
and the hide & keepers.

The show & tellers are very tempted to show the whole world their v0.1's. Be it in a form of a model, sketch or a very early version.

Most people have the weird nature of telling you only the bad criticism. It is an important fact to understand, so you don't abandon your project. You can write down these criticisms and improve your creation.

On the other side there are the hide & keepers. These idea-producers keep their ideas to themselves and are afraid somebody else will steal it from them and make millions instead of them.

What they need to understand is this rough statistic:
Every idea you thought about, probably 1000 people have thought about also.
From the world population:
1% have great ideas.
1% of them keep track of their ideas.
1% of them act on their ideas.

So telling other people about your precious idea will not open a contest to fulfilling it. Additionally, your ideas become your personal dream. Now why would anyone want to fulfill YOUR dream?

I'm more of a show & teller. I think the golden path is in the middle. One should improve his idea enough before showing it to the public. And when it's ready for the public, show & tell in every possible occasion and gain criticisms to improve.