Just like in real life, when you leave a comment on a blog you interract with a person. A real person who took the time to write an article which, for some reason, you find yourself reading. However, people never think alike so you might have a different point of view; no one said everyone must agree with what a blogger writes.
What do you do in this case?
In my opinion you have 2 options: either you close the webpage and think to yourself “what a moron to publish such stupidities” or you leave a comment.
Now comes the interesting part: it’s very important to be nice if you decide to tell “that idiot blogger” that he or she is wrong.
Think about it: when you were little, what kind of advice had more effect on you? The one that scared the heck out of you and made you grumpy or the advice you were happy to listen to because it made sense.
Nobody likes to be called an idiot face to face, so you might have to rethink the strategy when not agreeing with another blogger.
First of all, there’s a very high probability your comment will be deleted and noone will even know you were there or, worse, everyone will see you as “the bully”.
Second reason, you can be better than the rest and bring good arguments to the matter.
Now everyone will see how you outsmarted the rest by debating the subject with calm.
This way, not only will you have had an interesting discussion but may also have had a small impact on others, which brings us to the plus side: you might bring some new visitors on your own blog, if you have one, and maybe rise up little by little.
No one likes to waste time reading crap, this is why i think it’s more important to be nice rather than angry when having a different opinion that others.
Remember you are ‘talking’ with a real person so manners are always important.