Actually, no.
LFD was put into the game at the height of it’s popularity, during Wrath.
LFR was put into the game during Cataclysm; long story short, it was placed into the game to justify the expense of making raids.
Cute, but what I stated was true. People had to actually form groups on their own to complete content, which was in turn tuned for these kinds of groups. When they implemented the LFD/LFR systems, this meant that players no longer needed to form their own groups to “see the content”, removing a force that created community. Moreover, this meant that they had to create dungeons for an unstructured, uncommunicative group (this is one of the reasons people complained about Cata dungeons being “overtuned”); this meant a lowering of the complexity of Normal dungeons, which itself wasn’t exactly good for the game.
This isn’t conjecture; this is what happened.
You’re conflating LFD and LFR.
It isn’t a regression. Quite the opposite.