Notable means unusual/unexpected. The engineer(s) that invented the energy absorptive highway railing has probably saved hundreds of thousands of lives-- but finding their name(s) would be a serious research task, they were just doing their jobs. The man who bites a dog is an irrelevant trivia that has no consequence outside of himself and the dog's owner-- but there will be a hundred stories on it.

Fundamentally it's a flaw in Wikipedia's heavy reliance on media coverage which exhibits this bias most strongly. It's a total mismatch: the media is fixated on the unexpected and irregular, but an encyclopedia is about how things are-- not primarily about the exceptions.

Of course, Wikipedia is also perfectly happy to cite reference works ... but tabloid crap out volumes it be a huge factor and is also a lot less accessible.

I think sometimes about an alternative history where we prohibited newspapers and other current events media publications as citations for WP-- these problems would be diminished but I think the result would be a lot less good for the world.

It's okay that things are flawed... it's just important to be aware of the flaws. One of the ways Wikipedia deals with this is by having a higher bar for inclusion in pages about living people.