Mostly because I have a 'real' job as a leading artist in a video-games company, and starting these campaigns over the holidays leaves me with enough time to track both campaigns and to make sure they turn out to be a proper success. Also - I wasn't aware on how many campaigns failed when I started mine. I think indeed that it would've been more sensible to wait until the first campaign is over and will make sure that this is the case with future Kickstarters.
Don't see the answer to your question? Ask the project creator directly.