It is a good point to consider that each new account created can turn into a fully active member of the community, even if they just curate. If they also create good quality posts, then that only makes an even better platform with more and more different posts circulating around. At worst, the accounts made do nothing and in that situation, Steemit benefits somewhat as it now has a bigger userbase. It will be a combination of all of these, but the third situation will likely be the minority, leaving active members to make the platform grow. Just my thoughts.