Think of it this way: Each site is a total website. If you had to start one on your own, it would take forever to start earning with it. This way, you keep earning and don't have to do a thing other than write.
What I like is that I can write about anything, no longer having to write just on one niche topic. So what if one article goes to one spot and another to a different one? The views and money still show up the same way they always did, except now there is more of a chance for success.
It will be interesting to see how all of this works out, but I would continue writing hubs, because you never know when one will get chosen, and it might just be the one that goes viral!