In regards to the quitting after their first post:
I think most people tend to write a second, third,... post, BUT, rather fast they discover that after their introduction, 'the real game' begins...
This leads us again to those putting time and/or effort and/or money in or these who don't.
About your second part, MOTIVATION!
In my opinion, it has a lot to do with motivation. If you're truly intrinsically motivated, nearly everything will work out!