Well, he does not need to fight, so he has no desperation. He brings in 1m+ PPV buys. Likely more.
I don't think it's very hard to understand why he can ask for a lot of money, what you think about McGregor, his fighting skills and trash talk is not really relevant when trying to figure this out. Don't let personal bias mess up your logical thinking.
Edit: Also wanted to note I don't really care much for McGregor. I like to watch high level MMA, so if he is motivated and plan on fighting in a "sport" type of way I'm in. I'm not interested in spectacles or silly twitter posts, bragging and so forth.
I understand the frustration.