You must have had a very different experience if you think 'MySpace looked way more attractive compared to FB'.... MySpace pages were ugly as hell, with tiled backgrounds, autoplay music, and mismatched themes. Facebook was CLEAN, and everyone's page looked uniform and consistently styled. This lack of customization, I think, is what made it become so popular. That, and the feed; myspace never had the concept of taking posts from all your friends and putting them into a list that you could scroll through. You had to visit each page to see what was on it, and that meant seeing the horrible styling and autoplay music.
I attribute the success more to creating a tight and more complete personal network due to the campus focus early on. I do think the features of MySpace were a novelty that was also wearing off. And fb provided a cleaner bug free interface