Sure they can change a man. From a happy go lucky human to a depressed beat down shell of his former self. Happens all the time. Most women want to change a man after the courtship is over and marriage has taken place.
That was the case with my husband's brother. His EX-wife used to run him down in the presence of his own family. I will never treat my husband that way; he's my blessing. And I should say he treats me like a queen in return.
Maybe these people should try actually getting to know the other person, and WELL, before marrying.