Most 2D Mario games have unremarkable soundtracks at best. I don't know why this sub-series gets so much flak for it in particular.
I always felt the music here was almost on the same level as other 2D Marios outside of the noticeably low sound quality and a select few tracks from the first DS entry in particular that were just plain weak, I think the main ire is just that people really hate the Bah sound, not sure whether they hate it in concept (nothing wrong with dancing enemies surely) or because the particular sound bite used for it is like the benchmark of low quality sfx in the NSMB games.
Underwater stages would use a different effect to make the cheep cheep twirl, they should have had a unique sound effect for each stage type, nothing screams out of place like BAH in the castle back in NSMB2.
Basically I'm saying this soundtrack could work fine if it were suitably spruced up, NSMB2 did this for the title theme and credits at least and it made a world of difference for the sound quality in my books.
Still utterly disappointed that they reused so much music though, I was so sure they wouldn't possibly be that cheap...
I'm also still assuming the various reused stage themes outside of the new overworld and athletic themes are just temporary placeholders for the demo builds, if i'm wrong then may I be cast into a pit of BAH BAH.
Welp, I was wrong, cast me off into the pit of eternal BAH.