I often see players posting they only play plants or zombies. I wonder where is the rationale in playing only half the game. Even if you prefer one side, It's quite instructing to play the other side to gain better understanding of the strategies and cards you are confronted to when you play your favourite side. Another thing is that when playing one side only, you are often subject to substantial wait times when playing matches. If you're ready to play both sides, when yoy have to wait to find a match, you just switch to the other side of the force and have a direct match.