For sure Islam Makhachev is not really a likable guy like Khabib Nurmagomedov, I really think it is because he doesn't talk that much and his English was bearly understandable, but just like you have said he is a great fighter for sure,
Great fighters don't need bullshit, I like silent characters in the world of fighting except entertainment wrestling maybe they will play promos to attract the audience, Islam Makhachev is not a replica of Khabib so don't compare the two too much, they still have their own characters, but they are the greatest fighters and fighters undefeated, anyone has to admit their greatness, they ruined the opponent's undefeated record and any fighter who wants to increase the number of wins then don't oppose and accept the fight from Islam Makhachev.
I like silent fighters as well and just let their fists and legs do the talking inside the octagon. But people indeed have different personalities. Khabib has his own ways, he has a decent knowledge of English and he talks with confidence. I remember Anderson Silva has done the same although he did try to become a villain for obvious marketing purposes. Something likable could be interpreted as marketable. It is sad but it is the reality. Silent fighters and those who have difficulty speaking English usually do not have a huge market unless they are paired against popular fighters with huge fanbases.