Ok, I'm assuming you really don't know anything about Porsche's except what they look like, so I'm going to try to condense the previous answers into something you can understand. Porsche is a performance brand, and therefore performance is their main priority, not luxury so much. Because of that, a folding hard top would add a couple hundred pounds probably to the weight of the car, and that weight would be added in the completely wrong places. A cloth top is much lighter, requiring less bracing for the folding mechanism, less bracing for the top itself, especially up high (with the top up) where the extra weight would be. Secondly, Porsches are rear-engined. That is, the engine is in the back of the car, where your trunk is on a Mercedes. With the engine there, where would you put a hard top? The answer is, nowhere, there's nowhere to put it unless you made it a 2 seater. But that would just make for a messy retraction system to fold it forward. The trunk on a 911 series car is actually in the front of the car, and there's not enough room in it for a roof either. So, because of that, it has to be a soft top.