Seth-Moore
One itsy bitsy flaw with your ideal there.
Go onto the streets ask someone who Adolf Hitler is. They'll tell you he was a dictator of Germany who brought about the deaths of millions.
Now, ask them who Thomas Francis Jr. is. Some will tell you that he was the man who first created a vaccine for the potentially lethal infuenza virus, but, by and large, you'll get a heaping helping of blank faces.
My point here is that, those who bring pain and suffering, have always left a bigger impact than those who alleviated it. The meteor is famous, the people who fill in the crater are not.
Let's ignore the question of meteors- as a natural disaster, they possess no motive and are neither good nor evil.
Who's Neville Chamberlain?
Think for a moment. Now, who's Winston Churchill?
Did that second one come up a bit faster? I'll bet it did. He had a lovely set of radio addresses, after all.
Who's Chandragupta Maurya?
Consider for a second. Now, who's Ashoka?
Ask someone in India. The latter has a set of pillars, inscribed with his law, and is, I can assure you, more clearly remembered.
Or, let's take your example of Hitler.
I'd say just as many people are aware of the identity of Oskar Schindler.
Or, let's take your example of medicine, shall we?
Influenza as an epidemic (while of great significance to be sure), is relatively obscure.
However, Jonas Salk- inventor of the Polio Vaccine- is relatively well-known.
There are great villains, who are well known, but there are also great heroes, who have equal or greater name recognition.
Who stood against George Washington? A good many students would have a hard time with that one.
What was the name of even one police officer or politician who tried to stymie the civil rights protests of our just-past age?
In the end, while we may be impressed with the deeds of Evil, it will always be Banal, lesser, a passing thing to be destroyed and overcome.
Hitler himself, the man, is less famous than his Holocaust. And the world leaders who united to stand against him are, in the end, more justly famed than he, and more widely.