I would say the number of new accounts doesn't reflect the amount of people signing up for Steemit. I have two friends, which have signed up over a week ago and are still in the waiting line. It's probably more to do with Steemit's decision on how many new they let on the platform each day.
The ever increasing numbers of daily unique visitors which you can see in this report also indicates that the platform is gaining in popularity.
RE: DAILY STEEM REPORT JULY, 11TH ★ STEEM 1.18$ + 849 New Accounts