I believe that people have the right to an opinion. They should be able to express themselves any way that they like. If you wish to tell a person who is in high school that they suck and should totally just re-write a paper then that is your prerogative. One thing is true about this though, you will be hated. Most likely that person will be very made at you, give you a glare here and their, and make your life a living hell. So in my belief, I hope that nobody likes to be a disparaging person who only gives their opinion to make people feel pain.
With an opinion always comes a disruption of some sort. Like when a person edits your paper and tells you that some things are not possible, you feel as though, they should just leave and go to Venezuela or something. When a person gives an opinion, it can be either good or bad. When an opinion is good, like saying that a person wrote their paper really well and deserve an award for it, that person feels really good inside. When there is a bad or a mean opinion, the person who is receiving the opinion is very misguided. He or she is very angry and wishes that who ever gave that opinion needs to shut their trap and keep their opinions to themselves. This usually occurs when a person tells the truth, but then they realize that what they said was harsh, yet they still do not care at all.
An opinion can decide many things in life. If you tell someone that they did a really good job at something, then they will be pleased with you and probably will hope that you have a nice day. When you give a person an opinion like, you should totally just stop trying, dig yourself a nice big hole, and then drop dead, you feel lots of pain inside. The person who gave you that opinion has the right to give you that opinion I believe, but sometimes it is not necessary to be so harsh to another. I know for a fact that when people are told just to stop trying, they feel really depressed, usually want to hide in a corner or run away from their family. If I was given an opinion like that, I would definitely be crushed and I know that many other people in this world would be too. So for all you people who are malicious, you do have the right to give an opinion, but sometimes you should really think before you speak.