Depends on what you mean by human nature, I suppose. It's probably also human to have a limited amount of energy and attention to care about things.
And this is probably also a cultural phenomenon. For one, tribal identities have shifted towards more modern things (unlike, say, religion - though that's still very much alive). And since people by and large seem to have given up the workplace as a battleground and embraced their identity as consumers, they pour more energies into what they consume as a battleground. Choosing how to spend their money is not enough to assert where they stand. They must also fight it out - not organise themselves as workers for more bargaining power against corporations, but get on the soapbox and assert their rights as consumers to corporations.
It remains to be seen whether this actually works. The track record seems to vary, but the trend is not looking very good. Voting with your wallet, so to speak, still seems to be the most efficient approach. But, as I mentioned elsewhere, I suppose there's also the entertainment factor. Getting on the soapbox can be fun, and for some that might be part of the consumption experience.
