The editor's a creep. He's right, sort of, but he's a pathetic bitch who can only feel good about himself by despising everybody. He's not giving her a bit of tough love to give her a realization so she can move forward, he's trying to bring her down so she'll have a crappy life feeling pathetic and so will Shion (except in Shion's case, under his thumb). It's not like he's got any good intentions that would give him any standing to look down on anyone.
I mean, come on, he's confronted with a girl who just risked her life to come to someone's side, and he almost instinctively reaches for whatever buttons he can come up with to make her feel like shit so he can keep his prize pig mangaka isolated and so he can keep the superior sneer on his face. Guy could use a good curbstomping.