A lot of writers (myself included) tend to be very anal about the ideas we have, and whether or not they would make good books. While there is nothing wrong with that, it is probably not a good idea to spend more time working on the idea than it is the execution. When it all comes down to it, even the coolest, most wonderful idea won't sell if the writing is an absolute mess.
While this is a fictional person, the writer Kilgore Trout exemplifies this process fully. He is a writer who makes a few appearances in the books of Kurt Vonnegut. When his work is described, it is said that he "has great ideas, but is a terrible writer", and as a result he has a very miniscule fanbase.
The opposite can also be true. Real life writer Jim Butcher (who wrote the fantasy-noir books known as the Dresden Files) took on a bet that said he couldn't write a good book based on a bad idea. Jim said he could do it using two lame ideas of the challenger's choosing. The ideas that were picked were "Lost Roman Legion" and "Pokemon". What resulted from that was the Codex Alera series. Each book in the series averages at about Four Stars on Amazon.
The point here is that while your idea may be cool to you, it's not gonna mean a thing if the execution is horrible. Good writing can make a bad idea seem good, and a good idea seem great.
