I started exactly the same thread a few months after BCSL came out. I completely agree, and I thought it showed how DT writes songs, i.e. without the singer. So, the instrumental stuff gets adjusted to be perfectly meshing with each other, but then the vocals gets put on top. The "day after day, night after night" was the most extreme outcome of this serialization, where they were seemingly unwilling to change the background music, even though they realized that the vocals/lyrics didn't work at all with the music.
Yes, the lack of solos is annoying, but if you had the instrumentals with the solos, I think quite a few tracks would be clear winners in the instrumental versions.
rumborak