noblegiraffe, it is important to remember that TF is not a government scheme but a social enterprise. So TF is not an especially good demonstration of the government's energy for recruitment either, although the government is paying TF to expand its coverage.
Separately, on the topic of TF participants not being all that special: SaturdaySuperstore has it exactly right - the TF bar is not set so high that entrants on other routes cannot possibly go via TF, but the bar is set notably higher and the reputation and momentum of TF ensures it attracts lots of really impressive graduates. By impressive, I mean they have strong academics, the right interpersonal skills to teach, and the potential to be great leaders. They are the sort of people who can and do go on to take the most selective jobs in the country as alternatives - top management consultancies (TF was set up by an ex-McKinsey person, and many McKinsey alumni have participated), top tech firms such as Google, PE houses, the Bank of England, i-banks, etc etc. There are vanishingly few such folks on other routes into teaching. You may think that all those alternative employers are morally dubious or what have you, but they are indisputably tough places to get jobs at, and attract outstanding graduates.
TF graduates are then explicitly sent to tough schools in tough places, with a mandate to teach to a high standard and to act as a role model for high aspirations and ambition. A TF teacher can often talk with personal knowledge about what it takes to get into Oxbridge or Imperial, apply for a job with a top institution, etc.
This definitely represents a particular political philosophy that many people really do not like: elitist, too focused on the top end, etc etc. I personally think it's bloody brilliant.