Why do people argue that Private Health insurance companies like Obamacare which is "bad". Yet others argue?

That Obamacare will eliminate Private health insurance companies through competition. I've heard both of these and they seem to contradict, so I'm thinking both can't be true, or are they??
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The government public "option" will put private companies out of business. It will be sold 10% less than the private companies. Subsidized by tax dollars to allow it to operate at a loss(private companies can't do this). It will hold private insurance to standards that it doesn't have to follow. The few private companies left standing will be very expensive and cater to the social elite. They will get great care, the rest of us will get the scraps that are left over.
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