He wasn't gonna take a paycut to fight Jake Shields, Jon Fitch or Rousimar Palhares. Those guys aren't people you take a paycut to fight; there are a lot of guys that are worth taking a paycut to fight, but they aren't them. There's too little to gain (the notoriety you get isn't much unless you're looking for your name-maker win, like the guy who KO'd Palhares did; it doesn't help your ranking; it doesn't improve your stock; it doesn't advance your career; and it doesn't even get you closer to the UFC, since three of the WSOF champs didn't cross over to the UFC cuz' Dana didn't like 'em) and the compensation isn't enough. Askren could've beaten all three of them decisively and it wouldn't have done anything more for his career than being in ONE did-- it actually would've done less, since by now he'd have made less money, he'd still be retired (since Dana STILL holds a grudge against him and wouldn't have signed him and Askren's been pretty set on retiring at 33 while he has his health for a long time now), and the exchange for all that is he'd be ranked, like, 6th instead of 8th. Rankings aren't everything.
And not only does he have no say in the matchmaking process at ONE-- so saying he cherry picks his opponents is just completely flawed (and I think Sapo and Aleksakhin's performances against Askren prove that they weren't as overmatched and incompetent as people think-- Askren would've stormed through Nikolay like he did Koreshkov if that were the case)-- but he's only had one boring fight among his last 9. The rest have been pretty entertaining. The only way I can imagine somebody saying Askren's a boring fighter is if they haven't watched a fight of his since Lima-- otherwise it's like saying Demian Maia's a boring fighter (if you feel he's boring, too, though, then I can see why Askren wouldn't be your cup of tea.)