She said it was because of the word "hate".
Polish women do get stupidly unreasonable concerning this word. They act like it's worse than raping the pope to say it.
So yes they do have bad tempers compared to many other cultures. Don't try to understand the issue with certain words as it makes no sense and you will never know which are taboo until it is too late.
Also..."I will love you forever" in girl speak ACTUALLY means "I will love you until I get bored with you because I have unrealistic expectations and my dad always told me I was a princess who deserves the best....or until something better comes along...I also don't even need a reason to totally change my mind but when it happens you can be sure it will be YOUR fault"