Here's the other problem.

The more people who post and vote, the smaller each share becomes.

I'm "stealing" from you right now, simply by posting and voting.

The reward pool (including your fractional share) would be larger if I walked away from steem forever.

If we magically landed some big-fish off of youtube tomorrow that has over a million followers, steemit's existing 30,000 users will have their steemit-rewards-pool-percentage cut by at least 66% and many will be diluted down to almost nothing (below the minimum payout).

It's just like the Bitcoin miners. Fewer miners means bigger rewards (each gets a larger slice of the pie). Zillions of miners means tiny-if-not-non-existent rewards and only the largest mining-farms can afford to stay in business (business always creeps toward centralization).

Recruiting top-tier tallent to steemit would spell doom for the current top-dogs (as far as reward pool percentage), although it would very likely boost the value of steem back up above $1.00 USD (by boosting the market-cap).

So, they might be ok with that...