I would make the distinction between short posts and bad quality. Sure, not every short post will be good just like making something long doesn't make it good, but there is benefit for things that are interesting finds, put into an easier to digest manner. Personally I feel there is a happy medium to be struck here where longer posts (that are of quality) can get the larger rewards and the shorter posts (also of quality, requiring personalized added value) can receive rewards even if smaller.
I also feel that having good quality short form posts can provide those quick reads for prospective content consumers, who I feel are a great benefit to this site. While I could easily be wrong, I have concerns about only having content creators around. Unless your a high SP holding curator, there are limited reasons to be here. Imagine if major magazines or other well known blogging sites only got their content out to their contributors. The whole points (in my eyes) is to get exposure to the greater masses...which I feel can be done through various post formats.
Just my take, not claiming to be the end all on this.
I see your points, I guess I mean the one liner, and this comes into debate of what short, medium or long posts can be or are.
That I can totally agree with. I'd have trouble upvoting (and considering it quality) a post with a single line. I have to feel that value has truly been added in some way. I may not flag it, but I'd probably leave a nice comment trying to inform them what I (or the community in general) might need to see to get it upvoted/rewarded.
This is a newer area for Steemit users in general and we'll all have some subjective things to figure out on what we want to upvote.