What nonsense. In a free market economy, you vote every time you voluntarily accept an offer. Not voting for a corporation, a vote that costs you your own money, is a vote against it, because corporations die by default. If ever people stop accepting new offers, the corporation will die. They can't force you to accept an offer or to pay for an offer accepted by someone else.
With a government -- or a corporation supported by crony capitalism, which is just more government -- a program doesn't have to convince the payers that it's worth paying for. It just has to convince those with the power to take money from others by force to do so and give them some of it.
Incorrect. The libertarian government ideal is that the government's main purpose (and some would say sole purpose) should be to protect people against such occurrences. So there is most definitely a mechanism to protect people against aggression from those with more power; in fact, libertarianism is built on the principle which underlies it.