Seriously, Riot, you couldn't take a short bit to add some unique emotes if Cass taunts Katarina? Or have Garen say something funny if Lux is around when using his joke emote?
What's your excuse?
Rivalry is always a better spot for interaction. If you want to ask Riot why they haven't put emotes in ask about TF and Graves, or Zed and Shen. There's far more champions who have a rivalry and could use interactions than the two sets of siblings who actually get along.
Garen to Lux "My beloved sister, let' s crush our enemies!" ults her
Old champions OP
Seriously, the only reason is that older champions didn't do that. Interactions are a relatively recent thing recent thing. I think they started sometime around Lissandra? (She has them, right?) So any champion released or VU before that most likely don't have any interactions. That's really the only reason.
That said, I would love for them to eventually come back and make sure everyone has the interactions that make sense, like the mentioned Cass/Kat or Garen/Lux taunts or jokes. Its a really cool thing. I think one of the things I always listen for in LCS is Lucian's quote when he kills Thresh, and its just a really cool thing to remind you of the tension between these two, despite being picked purely for competitive play.
