It's a self-reinforcing thing. Corporations don't hire lobbyists until their interests are threatened by government. For example, Microsoft didn't start giving money to Congress until the DOJ started investigating them. Same for Google.

Once a company invests in lobbying, lobbyists have an incentive to keep clients on retainer, so they look for rent-seeking opportunities that they can justify on an ROI basis. Hence all the shenanigans around taxes. Spending $500k on a lobbyist to save $1 million in taxes is a no-brainer.