I think a lot of them are set in their habits, just posting the regular stuff and earning the usual on the ad networks. They have been doing this a while, and it is the easy way for them, cashing out on a regular basis.
They also got their followers, and a community built upon them. It might be they have not even heard of Steemit, it is not on mainstream media's antennas yet.
I had no clue myself when I was directed here in November. I even had no intention to start a blog, yet here I am, working daily on @theDolphin.
The big names WILL come as their followers get more used to the crypto world. Some will get into it themself, but I bet most of them will still earn their wages as today, by advertising channels and promotionals.
As someone who has seen how they work and everything, I can only imagine what kind of scammy bullshit they'd bring to the crypto world.