People said the same thing about Medicare, Social Security and Medicaid and they have become the most popular programs in the country.
In theory the individual mandate should bring down premiums. And if you look at Romney's response to the law he wanted to keep everything it provides except the mandate which pays for it. So he wants everyone to get the benefit but he doesn't want to pay for it. If he wants to counter with a replacement program he needs to start fleshing it out with some details because come debate time this current stance will not wash.
You raise some legitimate concerns, but you seem to imply that there's a choice between mediocre coverage and awesome coverage, rather than between coverage and no coverage. Something like one in six Americans have no coverage now. Without Medicare and Medicaid that number would be vastly higher. Obamacare is not supposed to directly effect people who already have coverage or companies that already provide coverage. Obamacare is not perfect nor does it pretend to be--much of its 2000 pages is to set up trial runs of differing programs to provide care and manage costs.
The system as it is pays doctors for quantity of patient treatment/ patients treated instead of quality, whether paid through the government or through insurance companies. That's a problem you seem aware of but it's a problem nobody has talked seriously about fixing. Scrapping Obamacare and starting from scratch is what Republicans said they wanted to do with Hilarycare twenty years ago. That's when the Heritage Foundation came up with what is the broad outline of Obamacare, including the mandate. Romney tried it out in Massachusetts, where it is a popular program that largely works. Should people wait another twenty years to get sick?
"...each of these programs that depend upon younger people supporting the elderly through government receipts will eventually be in deep trouble."
Nifty Affordable Care Act calculator from Washington Post online for readers to figure what the law means for them:
Mitt supporting the individual mandate:
Politics is easy. When a Republican proposes an individual mandate it is good. When a Democrat proposes it it is bad. When a Republican proposes it - it is about individual responsibility. When a Democrat proposes it - it is a tax.
Quit being stupid. This is so simple a Republican could understand it.