It might be because Steem blockchain could be viewed as a competing blockchain with eth. What Eth does, you can also do with Steem, but it seems steem might actually be a bit faster. This of course could be wrong as I am no blockchain expert and I could have been mislead by things I read.
I'm thinking it's a matter of competition. He has mentioned a few other blockchains in the past, including Blocktrades, but he always stays away from the subject of Steemit and Dash too. There is no way he is not aware of Steemit by now, he probably has an anon account just to stay on top of his game. By now, if he hasn't announced a blog in Steemit, is because he's avoiding it.
As I said above, I don't understand this. This is just healthy. This will force the developper to develop a better product to be really competitive and everyone wins.
I'm not saying competition is not healthy, the problem is when competition makes you do irrational things like risking your work to be all lost by publishing in less secure places. I'm actually pretty happy about him ignoring Steem because of competition, means we are doing good.
I was not referring to you btw, but to him (sorry for being unclear with this).