Let´s put it otherwise...you are in a Sushi restaurant and some guy or gal enters and says "well....you serve Sushi...I actually really don´t like Sushi...bye!". Would you think the same as you pointed out before, that this person is only stating his or her opinion? And if you think so was it worth doing so? If the person tried out the food and would say "I don´t like how you are doing your Sushi" it´s different and it´s a feedback. The idea of these threats, at least I think so, are feedback if you played the game and what you like and disklike, helping other people who are reading it to judge if they want to play it or not. If you do constructive feedback you might even help the dev. .