I think that more apps should look at charging for accounts.
I have some doubts if that is a promising way to go: in my reality I have to convince people to join STEEM (and yes, also Steem Monsters). It's not that they come to me and urge me to help them joining and using any STEEM application; no I have to convince them, and that's not easy most of the time.
Do you think they would still join if the first thing they have to do is to pay for something unknown, related to 'crypto'? Is half of the world impatiently waiting to join the STEEM blockchain (or does the average guy prefer to do what he has always done, using facebook for example)? I really hope in future people want to pay for being a member of the STEEM community (because of it's great reputation ...) but as of now we need new users much more than they need us.
What I wrote doesn't mean I am completely against charging for the use of STEEM apps, I just wonder if/how it will work ...