The reason is that the developers believe that the RC system will be much better along the line, since it allows for cheaper on-boarding of new users. Now that Steemit Inc does not have to delegate to new users anymore, all dapps such as Steemmonsters, Busy, Musing, DTube or any of these can create accounts for new users (for free), making it possible to get lots of new members more quickly.

And the intent is that new users should have enough RCs to interact with the blockchain without too many limitations, so we just need to wait until the system had found its equilibrium to see if this turns out to be true.