Someone will write article with his own experience but another person will say it is not true.. That means you are calling him a lier..
It does not make the writer a liar, mind you that someone could have good intentions, but still write an entire article wth erroneous and misleading information, would you rather other users allow such information to stand, or to correct such users so others do not take such information to be correct, to be honest i do not see a problem with that (correcting someone's mistake), it all falls under the process of learning, you make a mistake, you're put in the right way, you learn from it, and everything goes on fine; win-win situation for all.
And those people that condemn work are getting more merits than the OP himself from his own experience.
I hope this post isn't about merits which is a subjective case, the real point here should be what is correct and what is not, and if we can take merits to be something given for quality posts, then it is only normal that the user who provides the most accurate information would get merits for their efforts, irrespective if it is the OP or not. If by the way the OP provides accurate information, then the user could likewise get merits for their efforts, but it is really subjective.
In general, "just wear a thicker skin".