Let's say that steemit would have a total of 16,418,475 steem. But wouldn't that mean that the total value of steemit would be divided across the amount of steem currently available? This would pretty obviously mean that the value of steem currency would be much lower, as the currency would have less demand as a result of the new supply of coins.

And still, the thing is that bitcoin is very demanded, while the supply is definitely limited, as opposed to steem currency - both when it comes to the supply, which is not limited, AND the demand, which clearly is not there, since the currency is only worth 1.7 USD.