it was founded by a violent man ( he killed all the Jews in the town of Medina ) and in countries where the Koran is followed as law it is a very harsh place to life for women and violence towards them is encouraged ( beatings with sticks for looking up while walking and such ) but many Muslims do not live in Muslim run countries and are good people I am sure.
I think that most people like to make extraordinary and highly unlikely judgments about things they are totally ignorant of.
The vast majority of the population simply can't ever say that they don't know much about something.
Even though it should be obvious that people cannot possibly know a lot about everything, its like some terrible embarrassing weakness for a person to simply say 'Islam? I don't know about this culture.'...Their ego can't handle it.
After someone does something that people think is terrible and it scares them....The masses will look for whatever superficial quality which made that person different, and assume that this is the cause. They are too lazy and cowardly to examine the situation deep enough to actually get a good understanding about it.