The language that made it normal to blindly run code that you found lying around on some page? Elsewhere we'd call that a remote code execution exploit. JavaScript just calls it another day at the office.

And it's not fully sandboxed. It betrays its user all the time by abusing unrestricted access to the network, or activating browser functionality that most of us would disable if we could.

I'm not saying it's THE bad decision, but it is the product of a generation of thinkers who were not thinking about threats the way we do now. If we were to go back in time and have the opportunity to do it differently, I think we would take that opportunity.

But we don't actually need a time machine. We can just accept some sunk costs and move forward anyhow.