It is somewhat similar to phishing and people got trapped because of their curiosity and carelessness. If they can control their curiosity and carelessness, they can have better practice and they will have higher chance of maintaining and achieving higher security for their devices and accounts.
That's some people's work btw...
They just have to be curious to arrive at something, and let's just say they just have to do it. It's simply better to take any sensitive data off those working PCs and keep it cold.
Using an offline password manager is still better, but as long as it's still on that PC, it's not truly safe. So, my conclusion is that this is partially due to carelessness and curiosity.