It most likely means we have 10s of thousands of people who created accounts (just to reserve their preferred name), but have no interest in investing in yet another social media platform until the network effect is there and their friends ask them, "Hey, are you on Steemit yet?" and they can reply, "Well of course, I created an account way back in August."
I've done it myself on multiple social media platforms. I reserved an account... never found a reason to go back.
As for some investing in steem via their fiat, I have zero problem with that, just as I have no problem with them investing in any other cryptocurrency. A steem account isn't just a social media account, it's also a wallet and, in a sense, a bitcoin address (but for steem).
It could also mean there are 10's of thousands of bots too. :)