Buying out the People

So, I thought that the whole idea behind capitalism was supply and demand. People want item A. Company makes item A. People buy item A. Company makes money. When people want item B company stops making item A and makes item B (or company closes because another company is making item B already and there isn't enough demand for 2 companies). Makes sense, right?

So what's with the string of recent government buyouts? First it was the Stock Exchange. Then it was some banks. Most recently it was several automakers. What happened to the capitalist idea that if company can't make what is in demand it closes? Why is the government using taxpayers (the consumers) money in order to pay to keep open that the consumer's have said they aren't interested in buying?

Hey Capitol Hill, if it can't survive in the market on its own, then let it die! (Otherwise there will never be any room for the market to change and evolve.)