The miner nerf is justifiable

As of right now, the miner is in the top 3 most used win conditions and has one of the best win rates in the entire game. This card is especially good in competitive games and used widely by many pros. It is guaranteed chip damage for 3 elixir and because it doesn’t need support the rest of the deck can serve to play perfect defense. I would like to know why so many people are complaining about this nerf.