If you're worried about tracking, you can block ads and tracking scripts without disabling javascript. If you're worried about viruses, well, all I can say there is that in my experience and understanding, if you keep your browser updated, the odds of getting a virus via browser JS are exceedingly low. Doubly so if you're not frequenting sketchy sites.
I don't know, it seems to me like advice from a time before security was a priority for browser makers, and high-quality ad blockers existed. At this point, I really don't see the value.
Javascript is a privacy and security nightmare. It's almost equivalent to downloading and silently executing untrusted code on your machine. I say "almost" because Javascript code is virtualized and sandboxed. Though I have no doubt people have already discovered vulnerabilities that enable code to break out of the sandbox.