It's pretty much human nature I think. Something looks like easy money and when the going gets rough etc etc. It wouldn't surprize me if the dropoff rate with blogs is similar to that of adult webmastering in general.
I started my blog as a hobby and manage (so far) to update it once or twice a week. Since I don't expect to make any mony from it any time soon I won't let it steal time from what
does provide a modest income: Building and submitting, building and submitting...
