What they don't notice is that all the good ranters provide much more than just shouting "I DON'T LIKE IT" really loudly. A good ranter makes accurate, insightful observations the average person would have missed, like in the Plinkett Star Wars prequel reviews. Millions of people can (and do) whine about how the acting was wooden and how Jar Jar was awful, but only the Plinkett guys could point out specifics about how the movies didn't have a protagonist or that there was way too much dialogue about a trade dispute.
Plinkett also offered his viewers pizza rolls. That's called being considerate.
People didn't put a whole hour of time into watching their Episode 1 review just because Plinkett dared to insult Star Wars, but because they did it really well and pointed out things we never thought of or couldn't put into words. The average Phantom Menace-despising person has no reason to pat themselves on the back for making comments as incisive as "That line about sand was very bad!"
Even worse, what if you later find out you are wrong? Maybe the thing is actually pretty good and you misunderstood something or didn't get it. Ten years from now when you finally get it, you will want to put a bag over your head when you remember how proud you were.
After seven years of calling out the lies in Batman Begins, Calvin learns it was not a documentary.
I'm not saying you should feel bad in any way about hating Katy Perry or FarmVille -- those are valid and probably correct opinions. There's just no reason to be any more proud of it than there is to be proud of not sticking your finger in the electric socket this morning.