There seem to be two conversations going on here.
1. The Report
Sure you can, but be empathetic to the person you are criticising. A journalists personal views are worthless. It's their job to live in the views of their subject and tell the story from this perspective. They may then objectively apply other judgment criteria. Its called a 'report' for this reason. But the report spited which initiated this conversation was absurdly biased, it barely even qualifies an an OpEd.
2. Our personal views
Khabib has no right to criticise McGregor for adhering to western cultural norms, but then I don't think he ever has? Any allegation Khabib has made against McGregor has majority support across the western world. As for criticising people from other cultures, it's Khabib's risk not to conform if he wants to pocket all the $$$ from another culture, but that's about it.
I don't think that Western culture is superior than others. It's simply an opinion on how life should be lived, and there are many such opinions around the world. As a Westerner, you are most welcome to criticise him, but why are you so surprised that others will find your criticism naive or unsophisticated?
It's not particularly his personal views though in fairness. I'd say by definition of journalism it hits the criteria pretty well, especially for MMA standards. I think it's perfectly fair for people to hear both sides of the story. We've heard all week what a great athlete Khabib is (and he is.) But then with anyone it's only fair to hear the flaws of the person as well, especially after some of the stuff with Khabib was putting him as this angel outside of the sport when the reality is far more complex than that. Course we've not lived under that lifestyle Khabib has but for me that doesn't mean we can't criticise him for certain things.
I don't think Khabib is adhering to "norms" though particularly. I don't think the "norm" is hanging around with dictators for example and some of the stuff he says leaves a lot to be desired. Equally with Khabib it's not like he's lived stuck in Dagestan forever, he trains out of AKA with plenty of people who are not from that culture and therefore he
should be slightly more educated than the stuff he says. I think even being generous with him and saying some stuff is out of his hands in regards of what he has to say in front of dictators, he's said plenty of stuff on his own free will which can be described as ignorant at best (homophobic and sexist is probably more appropriate.)
Regarding McGregor he did criticise certain western norms, he criticised him for lifestyle choices regarding acohol/drugs which are a culturual thing and are impacted by the society you are brought up in. He accused him of being a rapist which obviously isn't normal but equally there's no charges of it and it's a pretty strong alegation to throw at someone.
I don't particularly think it's unsophisticated to criticise it and I'm intrigued as to why you think that is the case? If you read up on something and form an opinion that's the complete opposite of being unsophisticated. If anything I'd say if people can't see the other side of the debate or argument and are blinded by their views and beliefs then they are ignorant themselves (not talking about you there by the way more of a general comment.)