dirty ignorant b*stards

I went to visit a relative in hospital today and I was appalled at the amount of other visitors who failed to wash their hands or use the alcohol hand gel on the way into the ward. This is despite the fact that hospital bugs seem to be in the news every week, despite the fact that there are large, obvious signs all over the hospital reminding people to wash their hands and despite the fact that there was a prominent dispenser of hand sanitiser right by the door of the ward.
I actually challenged one man who had blown his nose before entering the ward right before me, but who walked straight past the dispenser. I stopped him and pointed out that he needed to clean his hands. "Not me" he replied "I am clean".
Well, that was like a red rag to a bull, as I explained to him that actually, no, he wasn't clean, that he was risking the life not only of his loved one but also of all the other people on the ward. I pointed out that he would probably be among the first to complain if he or a family member contracted MRSA, and told him that he clearly did not understand infection control. His response was to shrug and walk on regardless.
Why are people so stupid and ignorant? Why do they not care if they are endangering the lives of others? Are they really so stupid and selfish and utterly lazy that they cannot be bothered to just clean their hands? It takes a couple of seconds and can and does prevent illness and death. Why the hell would you willfully ignore that when visiting the hospital? Sometimes I really hate people.