I took the time to think about it and I (respectfully) disagree. Different times have different rules. In the 30s, for instance, manners in public were very important. On the other hand, beating up your wife and/or your kids was considered a strictly private matter (at least in Yugoslavia and in France). You could publicly say some terrible things about Jews or Black people back then that would have hardly raised an eyebrow. Racial segregation was the norm in the US.
What I'm getting at is that our time doesn't consider being rude or outspoken or whatever you want to call it as 'crossing a line' - unless you're a public figure but that's a different matter. It's a long debate that would take us too far away from Lucas Moura but I think the relationship between clubs and their supporters has changed a lot over the past 25 years. At some point, we were treated like customers and, as such, some of us feels they have every right to complain.