Why muslim have to wear little hat like jewish? Well, the hat muslims wear is totally different than the one jews wear, therefore i think there is no comparison between them. Also i don't think that they have to wear it, it's just a traditional clothes in the middle east even before islam but maybe with the time it has been changed or turned out to the new shape which we can see these days. This is my opinion.

it's not a must , must have to wear it i think it's traditional before we say religious not all muslims wear it and it's different from jewish , jewish's hat is half way , smallest and doesn't cover all the head , but muslim's hat is complete and cover all the head :D