Given enough time, people forget. Besides, the people today need the fame. The people 50-60-70-100 years ago don’t need the fame anymore. They’re dead.
So new people get the fame. I just roll my eyes a bit when I notice it. “Oh look, that’s just a reworking [x]’s idea… oh wait, it’s not even reworked, just reworded”. “Oh look, someone dragged that old theory from the dustbin and stuck their name on it. Groan”.
To me, makes Science look bad when that happens. But, as most don’t seem to notice or mind, I guess it’s just how it goes.
I notice though and I like point it out when I see it. They got their fame off of somebody else. I feel justified in pointing a finger and going, “Bah, thief”. Maybe they didn’t steal and just happened upon things the same way. I mean anybody who reads a lot is likely to accidentally pick up combinations of words or proofs or ideas and not _realize_ where they came from.
Still, it’s good to know sources. I enjoy tracing back sources.