I don't hate the Oakland Raiders. I don't even dislike them any more than I do the Kansas City Chiefs or the Denver Broncos. They're just another team that the Chargers have to play against twice per season.
I hate teams based on merit more than anything else. I hated Mike Shanahan's Denver Broncos because they took out Jamal Williams' knees on every play. I hate the New Orleans Saints for (getting caught) trying to seriously injure opposing players instead of just trying to win by being the better team. For a short time this year, I hated the San Diego Chargers for what appeared to be reckless endangering the long-term health of one of their players.
The Oakland Raiders fans have a reputation for being a "rough and tumble" bunch, but that was mostly earned when they were the L.A. Raiders. Their players had a reputation for being a bunch of cheating brutes that would rather fight than play, but Matt Millen and Howie Long retired a long time ago.
Since I started watching NFL regularly, cheering for the Chargers on every Sunday, the Raiders have gone from one of the most fun teams to watch (playing beautiful football with castoffs like Rich Gannon, Jerry Rice, and Charlie Garner) to one of the most pathetic. Outside of playing good football and then bad football, I can find no reason for disliking the Raiders other than tradition, and that's not really my style.
If you're older and have been watching for decades, I suppose you have some sort of negative connotation to Oakland's football franchise. However, the team in its current state has a different person at the ownership, coaching, and playing level. If anyone has been with the Raiders for 20+ years, I don't know of them.
Sunday's matchup is a hugely important game because of playoff implications. The San Diego Chargers can not lose this game and hope to make it into the postseason without a miracle. That's why I'll be screaming my lungs out and jumping up and down on my couch. It has very little to do with the petty jokes I'll undoubtedly see on social media or a reputation earned by "the silver and black" long before my time. Does this make me a bad fan?