Your figures on doctors don't stack up - 40% of doctors represent in excess of 60,000 doctors - in the UK there is roughly one doctor per 400 members of the population, so those 60,000 doctors cover 24 million members of the population.

I do agree though that it is morally wrong that the UK as a relatively rich country with an established healthcare system not only welcomes but encourages skilled individuals to emigrate to the UK from countries that are in far greater need of those skills than we are in the UK.  That is another reason I believe our visa system for non-EU immigrants, (and the one proposed for all immigrants by the 'out'  campaign), is not defensible.