Taxi regulation is there to protect the customer, not to limit the market. Unfortunately, UK taxi licensing legislation allows a licensing authority to have a numbers limit, so capping the number of market operators. When I was a taxi licenser every time limits came up I voted against it, but the votes went for the cap. The regulators aren't (shouldn't be) in the business of guaranteeing taxi drivers a job, they are there to protect the travelling public. If the market can only bear 1000 drivers and there's 2000 drives, well, then, 1000 of them will go bust and (should) realise they're in the wrong job and move into something else.
Uber is just the latest method of hiring, all the way from waving in the street, to sending your servant, to using the telephone, to using email, to using a website, to using SMS. Uber is just another taxi control office.