To approach your points individually:
- The wider middle-class in the US are used to paying for quality. It's not so ingrained in the UK mindset, where we have been used, up until recently, to government subsidies.
- The UK market is still emerging. Note that charging $14k is only available as of next year - and will most likely continue to rise. As it does, fewer will go to university and the 'value' will drop.
- US Faculty do have higher salaries (~x1.5 - x2.0 in my experience), but good people are deserting UK universities in droves because of massive cuts in salaries, conditions and facilities. My own research group had seen 4 people from 25, including 2 faculty, leave in the past 12 months for better-paid positions abroad. I expect that we'll see another 5 go in the next 12 months. None of them have been replaced.
- Typically, a college degree in the US has been worth the outlay. It's only the last 3-4 years that people have been questioning the worth of the college degree as an investment en masse, i.e. the US market is not currently stable and won't be so for another few years as people begin to reconsider what was previously a no-brainer. This will eventually translate to higher social status for a degree (as used to be the case) and cheaper prices (and so less debt necessary).
- In the last 10 years, in the UK we have begun to view a university as a business. We're asked about cost centers, what we can sell commercially and requested to make PR material for wide circulation. As a business, we are forced to charge what the market will bear. But because there's not a huge amount of competition between universities (at least on price), that doesn't make for a particularly healthy market.