Fair enough, if you feel that way. I still stand by the fact that you're only talking about london here. Up here in Manchester the people with houses are people with rich parents who then let their son/daughter live in it, and get rent from their friends, but thats still very rare. Looking further afield from london, your points become less valid.
Also, the travelling expenses and stuffis a fair point, except the figure of £20k quoted is after 2 years, and to my knowledge, medics don't reeeally go on placement until 3rd year (though i may be wrong), so that figure for people living outside of london with no mortgage and not on placement (ie. most 1st and 2nd years), it still seems dubious how they've got into such debt.