I'm not saying I don't think it would be a good feature, but steemit.com is a fully-owned product of steemit inc. They are entitled to decide what features they want to offer, considering all manner of factors. Since the concept of paying for accounts is quite obvious, they have clearly decided not to prioritize it or implement it at all for whatever reasons. These could include development but also support, legal, etc.

The blockchain, however, is open and others are free to offer services built upon it. If this blockchain is going to have value beyond just one web site (and if it isn't, then it is useless; running the website off mysql would be cheaper, easier, and more efficient) then the focus needs to shift away from expecting everything to be part of steemit.com and done by steemit inc (especially if Steemit inc  doesn't want it or consider it a priority).