I respectfully disagree. A win over Fitch or Burkman would have done a lot more for him than dominating Abbasov, who even though was on a nine fight streak, doesn't even have a wiki page. I know Shields and Palhares were still signed with the UFC when he made his decision, but a win over either of them would have been huge too. WSOF also would have kept him on TV instead of some obscure internet PPV.
At the time, the UFC stated publicly that they had no interest in signing him. Now, if you're Askren, you have a choice. Join a promotion like WSOF that might potentially lead to a shot at the UFC, where you'll fight potentially dangerous people that are, at best, past stars and past potential stars. You run the risk of the UFC continuing not to have any interest in you, because your name doesn't mean anything in the US, in the UFC's eyes.
Add to that, WSOF is a lateral movement at best, a lower-tier league than Bellator at worst. Not to mention, that any mention of your name is still going to have the * next to it in a lot of fans eyes, because you're not fighting in the UFC. Add on-top of that, that the UFC's maneuvering is clearly political, not actually relating to your true skillset and records. Even more, you have zero leveraging ability when the UFC does decide that you're worthwhile, because all the hype you had from being the Bellator champion will have died out.
As opposed to a promotion where you will make equal or more money, be a centerpiece of the promotion in an expanding market, have virtually no chance of losing or tarnishing your name and build your market value in the Asian market, a place where the UFC desperately wants to expand into. There's some of negatives of WSOF, but a lot more benefits beyond potentially getting your reputation a little bit higher, even when it should have already been enough. There's more leveraging power, simply because if he builds his name in the Asian market to a good enough point, he can headline Asian-centered shows.
I think he made the right business decision, if he's in it to make as much money as possible. If he's thinking about his legacy, maybe not so much.