On Amazon.com there is a very interesting review of the book "House and Philosophy: Everybody Lies". It states:
"House, M.D." is a show about Dr. Gregory House, a brilliant but misanthropic diagnostician with a razor sharp wit and a contemptuous disregard for the feelings of others. House has little use for hospital rules or medical ethics. He openly rebels against any form of authority that would attempt to interfere with his ability to do what he thinks is best. He abuses his staff, insults his patients, manipulates his friends, alienates everyone who cares about him, ridicules anyone who disagrees with him, and takes pleasure in making others as miserable as he is. [...] Although he doesn't really care about his patients as human beings, he is an obsessive puzzle solver; and he will not rest until he has figured out what is wrong and how to treat it. You wouldn't want House as your family doctor. But, if you were dying of a mysterious illness, you would definitely want House on the case.
My guess is: either some people don't care if they die, or they do not realize they are already dead.