I'm always quite concerned with these kinds of players. Hyped Superstars with ridiculous raw ability are nice, but they come with a very long set of requirements.
Juventus has always been a team of stars playing as a team. Ronaldinho is the kind of player you have to plan your entire team around... he demands it. This has its benefits, but also significant drawbacks.
Players like Ronaldinho bring a lot of press and a lot more scrutiny. Is this something a rebuilding team wants? Perhaps, but it depends on one's strategy.
He might be beneficial if it means more $$, better sponsorships and more kit sales, but signing a guy like that means tying the future of the team to him and his attitude... because not only do players like him demand it... but for the next while, the coffers would be drained dry and reinforcements will be few and far between as the old guard start to retire. Marchisio, De Ceglie, Giovinco, Nocerino, Chiellini and Criscito would have to become stars, as well as others internally, since Ronaldinho would eat up so much of the salary until the team builds up enough wealth from the Ronaldinho investment. He flops, Juventus flops... and thats not something we're used to with teams built for anyone to be a hero on any given night.