You ask interesting questions, that's why you see me here:-)

About statistics... Maybe. Probably something is wrong with the promo campaign. When people are told: "You can do here the same things as in other social networks, but you will be paid" people register and start doing the same things here, sharing other people's recipes, spreading funny pictures / quotes / memes. And then they are noticed by the Cheetah / Steemcleaners, they understand that it's hard to work on content and its promotion, that it's not just copy / paste for money.
Perhaps then they try to spread the original content, but they simply can not be seen behind a bunch of shit posts. I do not know about you, but it's hard for me to find something original and interesting in our "New". It will sound sad, but more often than not, my visit to New ends with catching cheaters. This may be the reason why many oldtimers are limited to voting only for people from the circle of their friends, without giving chance to beginners.
I'm not saying that everything is exactly so, it's just my opinion, as a person who spent some time here and looked around. I watched as some of my friends stop writing original stories and become shit-posters. Really, why do you need to work hard and waste a lot of time if, as a result, you get the same votes from Minnosupport, Busy, eSteem, Curator and 5-10 more random people. Due to unjustified expectations and lack of attention, even honest and talented bloggers can leave the platform.

But this can only be one of the reasons. When you analyze the level of adoption of a platform, do not forget about people who are purposefully creating accounts for fraudulent activities, such as post / comment farms, and then simply leave them after their scheme is uncovered and there is no more possibility to cheat with these accounts. One user can have 100-1000 accounts. You can ask Patrice how many names Dart has.
In addition, a large number of accounts are created for resale. They are simply created and waiting for their turn to be sold. Who wants to remain anonymous or unwilling to wait few weeks for confirmation, can buy it for only $ 10. Nearly 2,400 such accounts were created on one of the Russian sites as paid jobs. Yes, we lose a lot of accounts, and this is bad but not each of them is a real user.