It isn't clear how you are measuring attrition rate, is that someone that signs-up, upvotes once, and hasn't been back? I think this is to be expected initially in the sense that people are marketing their own blogs here, their (my) readers join to like or comment my articles, but it will take time for more than a couple of them to start coming here for any reason other than me.
RE: Measuring Steemit Growth: What Every Investor, Developer And User Should Know