The crap idea is an idea that has been 'outed' by being called crap and instantly receives unanimous disapproval.
Many ideas exist in a state of unconfirmed validity until either adopted or outed, being neither good, bad or indifferent. The difference with a genuinely crap idea is that once someone has outed it, everyone, including the originator of the idea, acknowledges that it is in fact crap and not only that but always was a crap idea. As in;
A crap idea always has a negative microgan value.
However, crap ideas can often lead to good ones. Many ideas have to be outed in order to make room for better ideas to occur, so the originators of bad ideas are just as valuable contributors to the process as those with good ideas. It was for this reason that Dentrition Meni Hangman II was invited to join the contiguation, having never had a good idea in his entire life.