My grandfather past away last year and, to this day, one of my fondest memories of my time with him was listening to him rant and rave about the ails of the world. Don't get me wrong, when he'd tell me things like he thinks all the homosexuals of the world should be relegated to an island and/or be shot against a wall, I'd argue and cringe at how ignorant his perspective was. His views, in my mind, were basically fucked. That being said, it was interesting and important to have someone so vocal from a different place and time.
Skateboarding has crusty, ignorant grandpas now! Let them talk about whatever the fuck they want. You aren't going to agree with them or be able to change their minds, so just smile and nod while they're still kickin' it.