People realize this, especially on HN. The post is referring to deprecations. You can patch security vulnerabilities and move a product forward without deprecations. Google does it well with Go.
Deprecated APIs, functions, etc, in many orgs hang around forever. They might not be ideal, but they still work for code written before (or even code written after that might have some perverse reason).
Google (outside of Android) doesn't deprecate, they rip it out. It makes things easier for them, as this post details at length, but it makes it harder for the rest of the universe.
Versioning and backwards compatibility costs a ton of money and blocks your innovation.
Legacy hell comes often enough also from dependencies you can't get rid of anymore...