So if he leaves alot will leave... then the reward pool gets smaller.
Well, no. It would get bigger. It would actually stay the same, but everybody's piece would get bigger. So, for example, the reward pool is 695,419 Haejin is taking 1% of that, he leaves 99% of that for the rest of the communtiy. Doesn't seem that bad, right? Well, there are currently 351,489,308,504,710,000 (that's 351 quadrillion) claims on that reward pool. So a 1% pull from a single user is tremendous.
The way I see it, hes not TAKING MONEY AWAY... hes brining new money in. Right?
No. The reward pool stays the same whether he is here or not. We could argue that the more users on Steemit the more Steemit will rise in value, but it could also be argued that if Steemit is seen as an unfair place it could cause Steems value to lower.
SO, if I dont upvote haejin and I read his analysis... then I leave the site and go back to trading... who benefits?
No one got my upvote... meaning i didnt participate in the reward pool.
Everyone on Steemit has an opportunity and a responsibility to direct the reward pool funds. You can do this by upvoting, downvoting, or abstaininig. @acidyo gave a good example of abstaining. The scenario you mention above would also be abstaining. The community at large benefits because their voice carries a little more weight because you didn't vote. Picture it this way. Your mom gives you and two of your friends the ability to spend 12 bucks at a casino. And tells you to decide where to spend it. She didn't give you each 4 bucks, she just gave you the ability to choose how it's spent. So each of you have equal say over 4 bucks. Friend 1 says put .25 here, friend 2 say put .85 here. You decide you don't want to put the effort into figuring out which game would be best and say you'd rather just go to the pool. Now your friends have control over 6 bucks each.
That 12 bucks is the reward pool and haejin represents a single game a the casino with 351 quadrillion games. In terms of overall benefit of steemit, many of your friends don't think putting so much of our funds into a single game is a good idea.