Secondly, more compressed (less dynamic range) doesn't mean worse, or better. It means more compressed. In some genres, tons of compression is desirable; in others, less so. Is an orchestral Hans Zimmer piece that maxes at -10 momentary LUFS better than a Skrillex song that hits -4 during a drop? You could argue either song is better, but I don't think your argument would have anything to do with its LUFS measurement.
Compression is similar to distortion. Too much distortion is generally seen as bad. But if distortion were always bad, people would use acoustic guitars and clean electrics and never run things through a distortion pedal. Same idea with compression. Too much compression will kill a mix, but not enough will reduce the impact the song has on the listener.
In other words, trying to say that LUFS is an "objective metric of quality" is complete nonsense. To me that's like saying that lines of code written is an objective metric of quality of a software developer.