When i listen to Rami i think he mostly talks about developers that do stuff like artwork, coding, animations etc ( the technical guys ) where you dont have to be a gamer to do your job. Where being a creative director or some designer you should play other games to diverse your skill. Comparing it to movies — maybe a lightning specialist doesnt need to watch alot of movies to know his stuff and do his job but i think director or screenwriter should know alot of movies especially from genre that they want to explore.
I think the knowledge how games are created ( the full process of making a game ) is useful to every kind of developer. And that knowledge is connected with gameplay and this one is connected with playing a game.
Also playing games has nothing to do with liking or disliking games, because you need to play games to create an opinion. You can dislike all games from the genre that you work with, but still knowing almost every major game in that genre because you played them.