Now, my 2k packs likely need to go to my deck, so can't be staked, and the whale puts 2k of their packs to their deck and the rest to staking. Now the whale gets infinitely more BCX than me.

I think you've missed a key piece of this - you can also stake the cards you get from opening your packs, and those cards can still be used in battles while they are staked in the airdrop conflicts. So if your 2k packs "go to your deck", you can still use them to participate in the airdrop conflict and earn airdrop rewards from that.

Additionally, the "whale" who buys 20k packs will have to purchase many more battle wagons than you to stake all of their packs, so they will have to spend more to earn their proportional rewards.