The number of words was just to answer your comment about an author who automatically gain rewards even posting 1 sentence.
With regards to the quality of the content, that's another story. Rules must design properly to avoid abuse and the with the existing smart people in the community, I believe designing and implementing the rules is not a problem.
That's not really an answer. You are suggesting a change which ruins the way the old system works but your solution to the problems is "someone else will think of it". Maybe the others will think of a solution or maybe not.