Ironically, it was actually Milton Friedman who came up with the idea for automatic withholding. He later lamented this after he realized the impact it had on the growth of government.
I think the initial idea may have come from the desire to enforce fairness, which is a great idea, but sadly it also led to tax increases being far easier to implement, as all the IRS needs to do is threaten to shut down a business if it doesn't make the proper withholdings.
As it stands, enforcing withholdings is the primary way that tax money is collected and it's taken extremely seriously by the IRS. There are even massive penalties for paying withheld tax late (something like 25% interest).