Not really where he was going with that. It's just like any episode on a sitcom teaching people that you can slack off and still come out okay in the end with no real consequence as long as you feel bad about it. We watch TV to be entertained, but that doesn't mean the values and idealogies do not run off while doing so. LFR while not a teaching mechanic, still puts in people's minds the idea that doing mechanics wrong is no big deal and offers little incentive to improve as a player.
Now, you can say you aren't playing to improve as a player, and that's okay. Maybe you log in and just like hitting buttons while fighting the big bads of the dungeon. That's fine, however, if you are someone interested in playing better and wanting to improve and enhance your playstyle, LFR does very little to help with that and in fact does quite the opposite. It gives people a false mentality that they are playing well and k ow what they are doing because things die.
As far as the phrases being made for it, let's face it, "looking for retards" could easily have been made up by a casual as much as a mythic raider. It got that term because you don't really have to have any idea how the fight works or even really pay attention to kill anything. Just look at LFR in Cata with Spine or Garalon, Amber Shaper, and Garrosh in MoP, fights where Blizzard decided to let players have some control over the fight and if done wrong would wipe the raid. LFR actually had some boss fights where 1 person could wipe everyone because they didn't know or care how the fight worked. These things (in addition to others) caused Blizzard to nerf LFR even more to make it even more accessible and easier for people to see content that it is a running joke among hardcore and casual players alike.