I blame Martin Gardner and his buddies for a lot of it, originally. Though Carl Sagan is probably a more direct venue for older dolts among these dreary be-knights of malapropism. Among the younger ones? Something tells me that Penn Jillette or Bill Maher might be their models of usage. Definitely someone on TV or whatever has taken its place.
If something isn't done there will have to be new entries in the dictionary,
- fallacy, n. A word meaning "I don't like what you said but I don't know how to refute it".
- evidence, n. A word meaning a statement that agrees with what the user want to be real.
- Occam's razor, meaningless expletive. a noise thrown at random into an argument that can mean pretty much whatever the person who threw it in wants it to mean but only on the occasion used.
I suspect the dulling of Occam's razor flows from some idiot at Newsweek who long ago said Gardner used Occam's razor like a switchblade. Well, no, he didn't, though it should be remembered that switchblades were a popular weapon among thugs*. Gardner was not infrequently a dishonest phony who depended on the prejudice and ignorance of his audience. And their fear. A lot of what he wrote was bullying that was most effective among insecure people who were afraid other people would find out how ignorant they really were, and how little they actually knew about mathematics - thus his popularity among magazine and features writers. That's the crowd who continue to grind the term down to a meaningless and dull slogan that couldn't be useful to pick your teeth with.
* When he knew someone had caught him in a lie or a lapse Gardner could certainly act like a thug, as pretty much are Penn Jillette and Bill Maher. Sagan was notably not thuggish but he was often way too full of himself.