They create far more negative externalities?
They literally can and do pay for laws written in their favor, to entrench their interests, limit their competition, and adjudicate their behavior? See, even they agree they should "pay more."
And because obviously they have more to lose if government services decline. They are the primary driver of demand for government services. Many of them need a functioning military, aviation, infrastructure, law enforcement, patent office, and other services to continue to make their billions.
If all the highways, gas pipelines, airports, Internet backbone and the Pacific Fleet in America crumbled to dust tomorrow, I'd be greatly unhappy but WalMart, Amazon, and Facebook would be ... well let's just say disproportionately affected.