I'm not sure that this is necessarily a welcome shift. Sure, as far as tone goes, it is positive, but trolls are generally not purely spammers or spam bots. "Pixies," as you call them, seem to clog up meaningful discussion in a way that even trolls did not. Pretty much every post on a platform like this is filled with pixie comments, and it gives a distasteful impression to those who are new to a community. It makes it seem like the only reason people use the site is the hope of making a quick buck. If Steemit wants to remain long-term and attract an average user, it needs to distance itself from this phenomenon in some way, at least in my opinion.