I am not a fan of any of those fighters mentioned, although I do respect their skill. I also enjoyed Conor while he was fighting, I don't enjoy him running away from challenges, being a twitter warrior and throwing dollies at people that have nothing to do with him.
Completely unrelated to that, I am a big fan of Khabib because I enjoy watching his fight and I like his grounded and humble personality. I enjoy that he's a good role model for kids and he's pretty funny too imo.
I'm sure there are many fans that love Khabib for the same, similar or different reasons but he has a legit fanbase and it's pretty sizable.