I doubt the lack of 6-door cars has much to do with aesthetics. Doors and tight door seals are some of the more complex and expensive portions of the car body. Doors also pose challenges for crash safety as you have a large opening in the car body weakening the main body’s structural integrity in an accident. I suspect that the reason there are so few cars with 6 doors is the extra cost of manufacturing cars. That would lead to increased car costs. Most purchasers don’t value the extra convenience of the additional doors enough relative to the added price. Any company producing such a car would find a very small market which might make it not worth it to the manufacturer.
I doubt the lack of 6-door cars has much to do with aesthetics. Doors and tight door seals are some of the more complex and expensive portions of the car body. Doors also pose challenges for crash safety as you have a large opening in the car body weakening the main body’s structural integrity in an accident. I suspect that the reason there are so few cars with 6 doors is the extra cost of manufacturing cars. That would lead to increased car costs. Most purchasers don’t value the extra convenience of the additional doors enough relative to the added price. Any company producing such a car would find a very small market which might make it not worth it to the manufacturer.