Mary was praising Jesus, honoring Jesus, in effect, worshipping Jesus, sacrificing to Jesus. Many people today are concerned with right beliefs. Right beliefs are good. We need them. Many people today are concerned with right behavior.
Right behavior is good.
Mary shows us right emotion, right feeling. The heart we need for God is an intensely personal devotion, a powerful dedication of ourselves to his service. This intensity of emotion is unusual, and like most unusual things, this was criticized. This kind of devotion was not within the ordinary range of acceptable behavior. People would call Mary eccentric, maybe even out of her right mind.