It's not designed with any common sense in mind. They just figured they could a) cut costs and b) make the vehicle look "cleaner", because Musk and the people who work for him are intellectually incurious morons who refuse to learn why things are designed the way they are before trying to reinvent them.

The thing about breaking the rules is that if you want to really do it well, you have to understand why those rules exist in the first place. That's hard to do when you start from the position of just assuming that you're smarter than everyone else.