Srila Prabhupada taught us that parrot-like, mechanical chanting is a pitfall for one on the path of transcendence. In the beginning, during the offensive stage, it’s forgivable. But after years of practicing bhakti-yoga one should at least graduate to the clearing stage, chanting with greater attention and love, and following the principles of bhakti. Niyamagraha, or being overly attached to ritual, is an obstacle to achieving spiritual perfection.