You can only vote once in 4 years. I, on the other hand, can stop paying any private company at any point in time if I believe a company hurts me or other members of the society. I don't see how that situation makes a company less accountable.
In practice, private companies don't need to maximize profits at the expense of poor. In Russia, for example, ISPs are competing hard against each other and internet is dirt cheap, you could have a 30mbps connection for around $7/mo. No regulation.
But suppose you're right. Suppose companies would maximize profit and the way to do it would be by not providing service to poor people. It doesn't make it okay to steal money (in the form of taxes) from me. Ask me nicely and give me a REAL option to not pay, and I may as well pay even more than required. But IRS are not nice people. They make people's lives difficult at the slightest hint of tax evasion.
