Are people too overly opinionated?

I have found that being on my lott and on other sites like youtube, or anywhere in general, that people just love to give their opinion whether it was asked for or not. I can't read a single comment or discussion without some one giving there opinion, and it's always a negative one at that. why is that? do people have so much time on their hands that they spend all day negatively criticizing others with their opinions, that they don't have anything else better to do? It takes less energy to respond to someone in a positive manner than it does a negative one, yet so many people find it easier to do the latter. why is that?