Jose Berrios is a really good pitcher. "Ace" just seems like a thing we too frequently use to demean really good pitchers because they aren't a life altering Randy Johnson in their prime. Because, well, almost no one is so the criticism often becomes mean spirited. Not always, but it sure feels like it. Scott Baker got the same treatment during his stretch as a really good pitcher for us.
Additionally, I'd say the Aceiest Ace of all the Aces in baseball the last ten years (Kershaw) has been consistently mediocre to awful in the postseason. And that is typically a quality people associate with earning that label. Yet, many definitions of "ace" would purposely not count him.
It's ok to have your own ace definition, I just wish people would understand their definition and apply it fairly. It's ok to want a dominant, intimidating, Johan-level dude fronting your rotation. They just number in one or two handfuls most seasons leaguewide and are virtually unattainable if you didn't develop them yourself.