Do you think a 'quality filter' would recognize quality? :)
The idea is very interesting, but the question would be how to implement that in an effective way?
Apart from that I still think humans should just do the hard work to seek manually for 'quality' as well ...
I like how Reddit has their system setup. They have mods of a sub that are chosen to audit the content. I know that this is going to be controversial because Steemit tries to be Censor Resistant, but I feel like this would be a necessary evil.
Especially with Smart tokens this might be more possible.