I think everyone is entitled to their opinion. However, whether or not you verbalize it depends on the venue.
Do I go around saying my opinion of everyone’s hair, clothing, house, etc.? No. Not asked for, not necessary. Unless you ask. Then I will give my opinion but not harshly. It’s not necessary to insult someone or be blunt.
At work, I have a lot of opinions but think about who I am talking to and what the outcome could be. Maybe it’s not worth getting into a pissing match with someone. Maybe we used to not get along but now we’re getting along ok, and so I don’t want to ruin that.
It all depends. It’s a very broad question. Of course we’re all entitled to our opinions – you can’t change how someone thinks. I have a lot of thoughts and opinions but they usually stay out of my mouth.