Your original comment didn't stand "perfectly well on its own", actually. Decimate meaning to destroy or kill a large proportion of something is just as literal as the definition you're using, only the definition I'm using is much more commonly used and understood, so it generally takes precedence.

Everything about you and your smarmy act is redundant. Can you shut the fuck up? Thanks.

If you want someone to shut up on the internet, the best way to do it is to not engage them. Works just about every time in my experience. But you cared enough to engage and then engage again.

And if you don't like smarmy people explaining things with a holier than thou attitude, engaging in internet discussion might not be the thing for you, you little piss baby.