The game desperately needs to incentivize zombie play (for now)
...at least in the short term.
PvP* queue as a zombie is about 3 seconds.
PvP queue as a plant is roughly 500 times longer depending on the day/time. That's if you can get a match at all.
One or both of the following options could be part of the solution:
1) Enhanced rewards for zombie victories. This could be flat, or it could be dynamic depending on demand.
2) Offer discounted zombie packs in the store. Once enough premium zombie cards hit collections, the game will balance.
Any of these (or other) measures are only intended to be temporary, until you can get enough 24/7 simultaneous users for it not to matter. But we're not there yet.
I cannot or will not recommend this game to anyone in its current state, but I want to so badly.
This is the risk of creating a match system that is faction-based. Without assigning blame for that, you now must fix the imbalance or the game will fail in its infancy.
* While this is a PvP issue, it's not just a PvP issue: Every Hero quest line requires 3 multiplayer victories and many of the daily/hourly quests require Hero wins, as well. Those quests are key to advancing out of the newbie phase of the game, and acquiring better cards through premium packs.
If we can't complete quests, we can't play the game.
Btw, I do play as a zombie if for no other reason than to help someone out.
But I need plant wins, too. I'm not F2P but I haven't spent much and BY FAR the majority of my good cards/combos (including commons and uncommons) are on the plant side.
I'd love to play a great zombie deck but I don't have one.