Anecdotally, Atom runs fine on my MBP from 2012... Sure it's a bit of a hog resource wise, but I find that the benefits outweigh the cons.
I think that's his point. To some people, like leejoramo, if their text editor is a resource hog then it is not running fine.
Edit: Just checked, after using Atom for two days straight it is currently occupying 80MB of ram. Anecdotally, the claim that Atom is a resource hog is actually wrong.