I look down on antagonistic people who assume the worst in everyone

Specifically, I'm referring to those who assume the worst about others in every single possible instance, proceed to viciously attack and insult them, and then refuse to accept anything that does not conform to their negative outlook. If someone does something bad, it is always assumed that the person has ill-intentions, and no effort is made to understand the situation. Furthermore, if it turns out the someone didn't do it out of ill intentions, a lot of people will cry "bull****" and continue assuming that the person had the worst possible intentions, regardless of evidence. And if you dare try to question the statement that sinister motives were at play, you are either an idiot in their eyes or assumed to be justifying their behaviour and you get attacked, too. To many of them, it seems like the the worst possible explanation is always the right one. For example, there was one video of a dog on a leash dancing that was actually just a looped video of a dog standing up, and people started viciously accusing and attacking the uploader for animal cruelty by tying up the dog for too long. When I pointed out that it was just a stolen video and in that source video the dog was just standing up at its own will (and perfectly capable of standing in its natural all-four pose), the replies completely ignored the evidence and continued to assume that the uploader was an animal abuser. I mean I've even seen such antagonistic people attack toddlers, too.

Granted, I don't think it's wise to assume good intentions in everyone, nor am I saying that there aren't people with bad intentions. It's good to be skeptical of people's comments. I am referring to those who automatically assume the most malevolent intentions in someone, show no skepticism towards any negative allegation, ignore any evidence to the contrary, and respond in a vicious manner. Basically, I absolutely have little respect (aside from the average respect I give to strangers) for these type of people. Is this normal?

P.S. I am not referring to the passive cynics (those who see selfishness in every motive - in some ways I am a cynic too). I am referring to the antagonistic ones who jump to conclusions, assume the worst and attack people based on their own prejudges.