You don't do that walk away thing in your financial prime though. You do it in your last mini-contract years. There's also a huge difference between choosing career winning where you are part and parcel of the franchise, and ring chasing where the majority of your career you were on a struggling 1st round playoff team and just decided one day you'd try to get one. If I was holding 200m and thought an extra 70 would change 20 years of my career, I'd do it. I won't do it for 2 years of my career though.
Plus, this is why CP3 wanted that provision in the first place, so he could personally cash in. I'd hate to be the agent of a guy who turned down 70m more. Ok maybe hate is a strong word, but I'd prefer the 70m commission.
Regardless, who's to say these teams will pay that for these guys? I don't fully understand the verbiage of the CBA so are the teams required or just allowed to pay it? I wouldn't think you could require it.