For me it's simply down to
Not being German and not having a team in the Bundesliga that I really root for (Had a soft spot for Wolfsburg since they has Wolfgang Wolf as manager, it's just too perfect)
PSG & City owned by horrid backwards sh*thole countries.
Real & Barca being simply worse than Bayern in every way, especially Barca and their moronic Swedish fans.
Man U, Arsenal, Liverpool I have disliked since I was a kid for Aston Villa reasons. Chelsea I honestly don't care about, for some reason I don't mind them as much.
Juve are in many ways vile, but again I don't really dislike them. Used to hate Milan in the late 80's early 90's even thou van Basten is one of my all time favorite players. These days they are harmless.
As for Bayern I much rather see them win than any of the above ones although I rather have Dortmund win, or even better a team I actually like. But that's not gonna happen because neither of the teams I support are any good