What is there to understand? I don't 'understand' free form jazz or a lot of progressive rock music. I don't understand Mozart's use of secondary dominants and diminished chords to voice lead, but that doesn't mean I can't hear the melody, rhythm and musicality of the musical piece. That doesn't mean I don't identify musical ability. I don't think I'd ever like hip hop. That's not the point. My point is that there is so little musicality involved in the music as to make it virtually indistinguishable from other artists in that genre.
Well let's get to the first part. Kendrick Lamar is considered a fantastic lyricist with his clever uses of multiple meanings and callbacks to other songs/lyrics he's written in the past.
The majority of "good" rap is predicated on good lyricism and a great beat. Not poly rhythms, non standard tunings and dynamics.
You sound upset the color red isn't orange.