There is an obvious reason the government has such a large reach: they think they can fix everything with just the right laws, programs, and agencies. For the most part, it seems most citizens agree with them. Think about any government program or agency and there will be someone who doesn't want it to be cut. It's easier to add more things to make people happy than to remove some and anger people.
It seems that the longer a government exists, the more bloating it will become, which would probably be why most countries only last for about a maximum of three hundred years. Seems the United States is past it's expiration date.