All writers learn this, in time: don't show your work to other people until it's safely finished. Even discussing your unborn book in quite general terms can be such an undermining experience that, afterwards, you give it up and go to live in Guatemala.
The idea of withholding a massive secret is obviously quite exciting to some people. It is also the basis of much classic drama, of course, from Sophocles onwards.
In my worst moments, I think the biggest effect of 'Eats, Shoots & Leaves' was to kill the happiness of people who had previously skipped through life, unaware of all the atrocities lurking in the world around them.
