It is my considered opinion that most Americans really just don't understand Islam. And why should they? In terms of sheer numbers, Islam isn't a major religious or cultural force in the United States. Lack of contact with Muslims and mixed messages about Islam in the media contribute to most people having a vague and confused notion regarding the religion and cultural force that permeates much of the rest of the world.
For my part, I certainly am no scholar on the topic, but I spent the majority of my childhood in the world's most populous Muslim-majority country, and so I think I have an understanding of Muslims and Islam, experiential rather than book-learned, that most Americans do not. I woke early in the morning hearing the musical call to prayer emanating from the mesjid (mosque) in town. I accepted without question that Muslims had their holy day on Friday, just as Americans do not question having Saturday and Sunday as their weekend. I always knew when shops would be closed or have shortened hours due to Idul Fitri and Ramadan, and it didn't seem strange to me. Halal meat, prayer rugs, hajis... all these things made sense to me on a subliminal level because they were part of the culture. And by the same token, I knew simply by living in an Islam-permeated society that the beliefs and practices of Islam were very different from, and usually opposed to, Christianity. There was no "all religions are basically the same" nonsense.
If anyone had asked 10-year-old me whether Islam should be best described as the "religion of peace and tolerance", I would have snorted and rolled my eyes and proclaimed that a question too stupid to be borne. It is well known that even in largely moderate Indonesia, people who convert to Christianity from Islam are often targeted for murder by family members. I knew that even at age 10. But at the same time, aside from their killing of those deemed apostate, I wouldn't have necessarily characterized Islam as a religion of violent murderous extremism toward outsiders, because that hadn't been my observation or experience. Indonesia has plenty of groups practicing extreme fundamentalist Islam, but in the 1980s, there was little of that in my far east corner of the country, Irian Jaya in New Guinea.
Basically, I would have said that in general, Islam is a religion of laziness, hypocrisy, and treating females badly.