Fans who think "rival" means "Dick who I want to beat up" confuse me.

The definition of rival is: a person or thing competing with another for the same objective or for superiority in the same field of activity.

If anything a good rival isn't someone who's a prick towards you. There's nothing wrong with ones like Jun, Bianca, or Serena.

Personal opinions: Blue was a shitty rival with a bad champion team - he was an unlikable asshole - and Silver was a whiny piece of crap. Neither were exceptional rivals or characters.