#5 - Wall Street is as redder than Trotsky.
It's true. There are more socialists on Wall Street than anywhere in America, but they won't tell you that. Where were the cries of "Let the market regulate itself!" when the Fed traded Bear Sterns a pile of cash for a pile of junk to make them a palatable buy for JP Morgan.
#4 - Politics is good for business.
Why would you want to be pure capitalists when you can pay lobbyists to bribe congressmen to dedicate tax dollars to subsidizing your industry directly?
#3 - Infrastructural monopolies are limited-scope governments.
Ever notice that your cable company makes an awful lot of decisions for you? If there were no regulation of companies that own massive, regional infrastructures they'd be able to do whatever they liked with them. Think a competitor would come in? Ever try to figure out what it costs to build out a massive telecommunications network? Neither have they. The corporate socialists mentioned above made sure that they didn't pay for it. Your parents did.
#2 - The limited liability model of corporations is anti-capitalist.
I'm all for deregulating the economy, but Wall Street can't have it both ways. Government intervenes by granting special protections to investors. That's why companies go broke and have tremendous amounts of debt and shareholders stay rich. They're not liable for the company's debts beyond the initial investment of their shares. Try that as a private citizen. Drive your car into somebody else's and say that you're only liable for the value of the car you were driving. CEO's do something like this with companies all the time. I'm not saying it isn't a good model for building up business. I'm just saying that if you want government out of your business, then don't expect them to grant you special privileges.
#1 - We don't want to!
We may hate tax day, but we hate having no services even more. Increasingly people vote for government to be a clearinghouse for outsourcing the services that government has traditionally provided, but then they complain when ambulance service is sketchy or fire departments don't have the proper equipment to deal with large chemical fires. People hate their medical insurance company, and they sure don't want to pay the premiums on having FedEx deliver their Christmas cards. Start taking away those little hold-outs of socialism and see what people really think about it.