Yeah, I've got some real doubts about the sustainability of the platform as well. That being said, I have found several high quality communities (including the ones I mentioned) that are full of interesting people promoting quality content. At this point I think that growing circles like that is something I'm more capable of than contributing to any top down change. For instance, I've basically self-appointed myself the guardian of the #geology tag (not least because I'm by far the most frequent poster in it) and I've started giving advice and assistance to minnows swimming around in it. One of the biggest sources of attrition for minnows is that long, dragging early period where you get zero attention, and I've been able to help some of them past that who might have otherwise burnt out on steemit. (Though I hesitate to take that much credit- who knows, they might have done perfectly well without me.) I think that if more people sought out minnows to tutor and shepherd along, rather than leaving it as a sink or swim environment, that steemit would be a much healthier place.