Yes the bottleneck is an issue, but I believe it can be overcome. While I do wish Steemit Inc would quickly automate the sign up process, they are still in Beta and are fighting giants, so I'll cut them some slack.
I believe in what they've built so far, and since they left the experiment in our hands, we'll have to become the scientists/technologists/engineers/financial experts/community leaders/etc. to keep Steemit from dying or being replaced.
-Rob