the logic is simple
he is afraid to be embarrassed. which he most likely will no matter who he fights... his most prominent options are khabib and gsp
he skirrid bruh
And since he doesnt need the money... why would he do it?
I would respectfully disagree with this assertion that he is afraid to be embarassed. I may be from Ireland but far from a McGregor nuthugger and would be borderline fan, less so based on his recent antics which have been disgraceful and far from the humbleness that made him so endearing in the beginning.
How ever I digress - let me state some facts to support my argument that one of McGregors biggest strengths is his lack of fear of failure or embarassment.
1 - His bravado in predictions is part hype part putting immense pressure on himself to succeed knowing the embarassment of being unsuccessful
2 - Never turned down and opponent / style / late replacement / weight class (this is actually pretty ridiculous given the behaviour of most ufc fighters nowadays)
3) Took his loss like a boss - he was humiliated and embarassed with defeat to Diaz and rightly so after the shit he talked, he did his post fight interview in the cage, he did his post fight press conference, he answered every question thrown his way and didnt hide from it (cough Ronda cough)
which leads me to...
4) He demanded an immediate fucking rematch with the bigger guy who just choked him senseless embarrassed and humiliated him in 2 rounds to happen just a few months later!
*Also have you seen his touch butt memes or some of the shit he wears*
McGregor is alot of things, a narcissist, ego maniac, a thug based on recent behaviour
however one thing for certain is a huge key and contributor to his success (as with a lot of successful people) is his lack of fear to fail or be embarassed