Unlike other graduate disciplines, there are no bad med schools (not counting the Caribbean). Anyone who gets accepted to any US med school is incredibly intelligent and hard working and has the necessary tools to become a good doctor.
I see no reason why the government shouldn't be more proactive about addressing the ridiculously high tuition by subsidizing the cost of med school. My girlfriend will be graduating with $300k in debt, and will then spend 7 years in her residencies making between $45-55k. Her debt has served as a huge factor for her in deciding to enter a field where she can pay it back as soon as possible, as opposed to entering a field that she might like more and that would better serve the community as a whole.