Perspective

In my view, there is one powerful word in the English dictionary, which is the key manipulator of our humanity. It's "Perspective". Everybody carries their own perspectives. It defines what is important to them and what is not. Two people having a common perspective become friends, otherwise, they become enemies, in worst case. The depth of their friendship or enmity is define by the how much overlapping their perspectives are.

There is no perspective that is always right or wrong. Something you feel right may not possibly agree with the other person's view. He might have his own reasons to disagree with you, however illogical they are. Some times, a given perspective may appear right, perhaps just for a short period of time; however over a long run, it may be absolutely disastrous. For example, religion was formed to bring order in the chaotic society. Though it did well earlier, they are now driving us to religion wars. If people who developed religion foresighted this, there could have come-up with something better than what we have today. We are now too struck with our religion, which is a perspective though, to think of anything contradictory.

Secondly, perspectives of an individual defines his identity. Any contradiction to his perspectives make him feel threatened to his identity. The identity can also be called as "Ego". A person is egoistic, if he believes firmly on his perspectives, and self-center in them. A person is egotist, if he brags about his achievements, as he perceive value in those, and wants to show off to make others feels the same.

Finally, people are too busy in airing their own perspectives, despite wrong, to hear anything opposing. Many people are not realizing because realizing anything does not fetch them immediate benefits. People understand others views if they can easily relate to their perspective. If they could not relate, they feel that they either did not understand or it is stupid.

[There are many things in life that could be explained with one word "Perspective". I tried to cover as much as possible. For remaining things, you could come up with your own analogies]

Why do we Criticize?

By and large, people criticize for survival and/or for seeking attention. But, few criticize for well-being of the society. Survival instincts and attention seeking/identification belong to the basic traits of humans. These traits influenced prominently for building value system in the society. Fortunately or unfortunately, we associated Money, Status, Information, etc as societal attributes to our value system. Whoever has these in surplus matter most than those who don't have. Here, we concentrate just on information, which is a key attribute (in the value system), for explaining why we criticize, as criticism constitutes sharing of information. There are two types of information that gets shared: good and bad. Criticizing for good to happen is constructive criticism, whereas criticizing for bad to happen is destructive criticism. Generally speaking, the prevailing criticism is destructive criticism. That is, people are curious to know bad or weird^[1] things than good things; thus fueling bad criticism. In my view, I guess that this is due to survival instincts everybody has. To explain, if you propagate good about people around you, there may be a threat to your survival. In other words, propagating bad about your neighbor could boost your survival in the society.

Secondly, as said, humans love attention or identification. Knowing something important that others don't know is definitely a value to you, at least to show your uniqueness. And it's norm that society appreciates value, and values those who have value. You knowing something will attract those who wants to know something, especially bad or weird things. And people attract to those who know something, so that they in turn attract those who wants to know something. Most of the times, the information shared is bad (such as rumors/gossips) than good.

Some criticize something because they have no other choice apart from living with it. For example, if your manager is a bully, you criticize him/her all the time, unless there is an immediate choice of you moving under other manager or leaving the company. It's the same with other relationships also. Once you moved out of it, the amount of criticism will definitely reduces, and eventually fades away.

Lastly, few people who either don't care or feel safe of their survival and identity in the society criticize for its(society) well-being. There people are rare.

References:
[1]. Why People Believe Weird Things: Pseudoscience, Superstition, and Other Confusions of Our Time, by Michael Shermer, 1997. (Book: Amazon)