That's not speculation, a lot of things that the government has a monopoly on today (even things like fire departments) were once in the private sector and ran just fine. In fact, some things that were once heavily under government control became much better once the private sector moved in, like the internet.
Fire Departments are a terrible example for things "running fine", in fact, there was a story in Tennessee where a department let a house burn down since members had not 'paid their fee' (
link). Even further back, private fire departments used to mark the houses they insured and not help them if they were not, and sometimes obstructing access to the house if a rival insurer had the house when they arrived (
picture). How is this not better than having every pay into the service, especially when situations could arise where I have paid, my neighbor hasn't, and the fire jumps ot my house?
The internet being better after private industry came in was only the case for awhile. Look what is happening now, companies like Comcast have local monopolies, are capping bandwidth, and are increasing rates, and no one can move in to stop them as they just lower their prices (they can do this without cutting into profits) and price others out of the market. Also, how would private industry even be involved in the internet today, had not federal funding and a need for a secure, powerful military network been there to inspire the creation of the project?
If you want to say a business' only real motive is power, then you must be willing to admit that a poltician's only motive is to get more power. The difference between a money hungry business and a power hungry government is that I can choose to stop funding the business by not buying its products or services. I can't choose to stop funding a power hungry government because first of all, my taxes are taken out of salary before I even receive my paycheck. And even if they weren't, if I were to stop paying my taxes, armed men would show up at my door and imprison me/shoot me.
I am on the side of neither big business or big government, because often the two go hand in hand, but at least the business can't use threats of violence to force me to do things I don't want to do.
Businesses can threaten violence and get away with it as well - hell, we have a long history of businesses killing union workers and leaders (
http://en.wikipedia.org/wiki/Anti-union_violence), businesses like DeBeers have been abusing people for years, there have been articles popping up about the FBI busting people in Florida for abusing immigrants who are forced to work and live as slaves. Business is basically the same thing as government on a large scale, except that we don't vote for who runs a business.
Also, it should be noted I tried to convey that business' only real motive is profit, but in today's world power and capital are basically synonymous so we're basically arguing semantics.