I think the extremely stereotypical tropes were fully intentional. I think that's kind of why so many people, including myself, find them so endearing. We're familiar with their tropes from the get go, but giving them a face, and the ability to speak to them whenever we want to and learn more about their specifics, makes them characters that we can care about. Marriage and children also plays a large part in it.
I don't care that Cynthia is a stereotypical, cheerleader, airhead. She's my stereotypical cheerleader little airhead <3