For balance issues? Yes. If you don't want to play the game to the best of your ability, you can play it casually and be fine. But if you care about balance, you should be striving for the highest skilled play, which at this point, doesn't involve katarina in the slightest.
So if you're playing the game casually, you aren't playing optimally or taking the game seriously anyway, so why do you care about balance?
If you're playing to improve and compete, why are you complaining about a champion that has been shown to be sub par at a high level of play? Instead of working to improve yourself and grow as a player, you just whine for Riot to nerf them so you don't have to overcome an obstacle that better players have already overcome?
I don't see how either path ends with katarina needing anything but buffs balance-wise, and that comes from top level play.
EDIT:
Especially considering Riot boasts for League of Legends being the biggest game in esports currently. Shouldn't an esports game be balanced around competition and not casual play? Imagine if the regulation height of basketball hoops was 5 feet so elementary school kids could more easily reach it? Why should the opinions of the casual community affect the competitive community, people who actually could win or lose money depending on the changes?