Fans have big factor in the game they can distract the focus of a player especially if they create more sound and taunting gestures towards the player, thats why we have homecourt advantage and players are happy to play there home because they know they will be hype up by the cheer of their home crowd. Although they are trained to this but still players have emotion so provably they are been destructed at that time and also the bucks are also heating up at that moment.
Players talked about this, the fans of other team is not as big of a deal as actually moving around. Like for example if the game was played in just one court, for all 7 games, and the fans alternated then it wouldn't become a problem and that is the important part. So let's say you are a Bucks player, you go to Phoenix Arizona, that is about 3 thousand kilometeres away, so you basically go bigger than most nations ffs, and then you sleep there, or hope to sleep there and then you end up with playing games there, then you come back.
So, home court advantage means that you get to have your games at your home at first, that is why we saw 2-0 for home team many teams in history, you move nowhere, while the other team travels such a long distance, especially in finals after a whole years of fatigue, you end up travelling 3000 km and play a 48 minute high pace game? That is just condition killer for everyone.