Short answer
Constructive feedback can help a marriage, but repeated insults, humiliation and harsh criticism can damage trust and emotional connection.
Islamic Guidance
What Islam teaches
Islam encourages good speech and kind treatment. Correcting a spouse should not become an excuse for humiliation or abuse.
Practical Guidance
What you can consider
Discuss behaviour rather than attacking personality, choose an appropriate time and acknowledge positive qualities as well as areas that need improvement.
Sources
Qur'an 49:11; Qur'an 4:19.