I don't really know.
When i was a kid Yugoslavia had one of the strongest leagues in the world and most of us there supported a Yugo club and we didn't follow much of the foreign leagues. After the brake up of Yugoslavia, the Croatian league didn't offer much so we started following Euro leagues more. Serie A was the strongest so we had a chance to watch serie A football every week.
It's probably a gloryhunting reason behind my beginnings as a Juve fan.
We were Euro champs, we played against PSG in the European Super Cup in 1996 and we literally destroyed them. I think this was the very moment i felt in love with Juve. The football we played then was out of this world.
Zidane, Del Piero, Di Livio, Vieri were humiliating every single team on their way.
It was the easiest thing in the world to fall in love with Juve and most of my generation were Juve fans (many were Milan fans because of Boban. That probably explains why i still dislike Milan so much

).
Then there is Alen Boksic who is from the same part of Croatia as i am and who played for the club i supported as a kid. He joined Juve exactly in 1996.
Lots of reasons as you can see.