I think a simple way to improve the quality would be to let the posts gain value without a lilit in time. Because smart content take time to read, time to be writen and most of all it is valuable more longer. This is the difference between fast news and deep journalism, between a comment and a book,..

There is to variables : quantity and quality. Industrial times pushes us toward quantity but it has been seen that to prooduce in quantity, with an ammount of ressources (here it is time) limited pushes producers who cares about rentability to care less about quality. The attractiveness linked to the money is a sad but effective way to convince more people to come see what steemit is. And it is also a perfect way to free people from the need of a job they don't like or don't exerce freely.
Steemit limits the way we upvote to enhance a choice. This is to create a value of the vote but also to force people to think of what they want to upvote. So it s a paradoxe to push people to post so often. Or it is because they want the plateform to grow. But if it is that it is a bad move cause it will destroy what makes steemit so great. Again it is only my opinion and I don't blame cats or babies or food lovers. The system should be different indeed.