This is bizarre. Informative, factual posts that are not rude or insulting are "off topic" now?
It wasn't a grammar Nazi post or about a typo, advice/advise is a common and easily corrected error that should be corrected, and I did so as politely as possible. Most people would appreciate it (I know I would).
All you've done by removing a single post (with multiple upvotes) from the thread is increase the chances that other people will copy/make the same mistake.
Edit: in fact it's even more baffling than I first thought, you didn't even remove it, you simply moved it to a position where some people, if they get that far, will not understand what it's about.