Exactly, quality is what shoukd be looked at irrespective of the post length and basically I have no single issues with the length of a post provided it is quality  and informative but where the issue lies is with people who make unnecessarily long post that end up having no quality or passing no relevant information maybe in cause of making the post seem having quality.
What I'm saying in general is that, some persons at some point confuse quantity with quality and some persons think that simply because is lengthy,  it doesn't have quality but that isn't the case as I've also seen very short post doing absolutely well.