Numbers of new accounts on steemit are not rising more because hardly anyone knows it exists. I wouldn't know about if one youtuber (I think it was Dave Cullen) didn't mentioned it during adpocalypse on youtube when he mention new project called Dtube on Steemit as potential alternative to youtube. And that is it. There are currently 5 large youtubers (some often, some sporadically) uploading on D.tube and telling their audiences about it and hence about Steemit that I know about (@furiouspete123, @joshsigurdson, @pressfortruth, @stefan.molyneux and @styxhexenhammer) and there are some who did it few times and stopped (@jokerproductions for example).

I am honestly surprised that dapps like Busy.org, D.tube or even steemmonsters.com are not way more aggressive in bringing more people in because you cannot do a real business and have real profits just by riding a HF20 hope train and focus mainly on existing users out of which vast amount are dead accounts (user retention is another problem)