... is that those must've been music critics, not musical theater critics. He does loop in melodies and rhythms from previous songs as reprises within other songs throughout the show, which is all super-brilliant from a theatrical perspective, but for those who are interested more in a music perspective than a storytelling or musical theater perspective, then maybe-- *maybe*-- I can see why they'd be dismissive.
I can't imagine a musical theater critic finding this boring. Not a one.