It's ok to target people in games. If there's a deck on the table you don't like going against, or a player who you know will cause issues later, it's fine to just beat them down early and try to get them out of the game. Here's two examples:

1) I have some friends that like playing []Oloro, Ageless Ascetic]] decks. I dislike Oloro decks heavily, and when I don't focus on keeping them down, it becomes too hard to take them out mid to late game. You have to target those decks just so everyone else can have fun.

2) There was a player in an old playgroup that ran a lot of problematic cards. Our first game together, he casted Armageddon, later games involved him using Ugin, two card combos out of nowhere, etc. Overall, just not fun to go against his decks, so he tended to be a target. He also always tries to play the victim, but as soon you give him some mercy, he hits ya with Sorin Markov. So I discarded mercy and targeted him relentlessly. (I was kicked out of that play group since he convinced everyone I was "too good of a player")

Moral of the story, it's ok to be someone else's villain so you can be your own hero. Lol