Some people believe that people should just say what is on their mind so that everything is out in the open so that everyone can clearly understand what is thought about any particular thing or person.
However there is an instinctual and social reason that many people do not say everything they wish.
People generally do not want to be seen as condescending and over opinionated or any other negative trait that people may think of them.
People wish to be liked. Being liked has many advantages that greatly overrule being correct or even perceived as correct or asserted as correct.
So in doing so the lines of communication are cut short in hopes that a positive outcome will result. That does not always help however. There are two main groups of people. The people that do wish you to voice what you are thinking as they will not be upset about what you have to say and will be OK with refuting what you are saying or in many cases even accept what is said as truth and learn from it.
Others however do not wish to believe what is said and will become resentful to the person asserting their thoughts as truth.
The general rule of life is that emotion greatly overpowers logic. Logic however is very important when it comes to severe consequences. The key to knowing when to assert your thoughts as truth is to know if the situation is petty or not OR if the other person is completely happy with hearing assertions even if they do not agree.
People are easily offended. That in no way shape or form means to hold all thoughts and opinions.