I had an interesting conversation a couple of weeks ago about the number of seats in cars. It was the oddest thing but they said they decided not to buy a Chevy Volt because it only had 4 seats. It became a point of contention because realistically, every car only has 4 seats. The hump in the middle of the rear bench isn't really a seat. It's uncomfortable and ergonomically questionable and if you're an adult, it's essentially unusable.
What made the conversation weird was that the guy I was talking to had no children, so it's not like he needed a bench seat to get three kids on.
Rear seats have been a point of debate for me for years. Hands down the best vehicle I ever owned for rear seats was the Honda Element. It unashamedly had four seats. The two rear seats were physically separate from each other, meaning great shoulder room for passengers, and they had plenty of space to the seats in front, meaning great leg room for taller people. (I often have 4 people in my car.) They were comfortable and uncompromised by the desire to have a fifth seat in the middle.
The same is true for two-door sports cars. Ford Mustangs, Subaru BRZ and such - why the manufacturers put anything in the back is beyond me. For any reasonable driver, the front seats have to be in such a position that the rear seats have literally 10cm of space between the front of the seat base and the back of the front seats. No average human could ever sit in them.
I feel the same way about "third row" seating - sure you get two extra ones in the back for dwarfs or people with no legs below their knees, but you lose all cargo capacity so there's literally nowhere left to put even the smallest bag.
I guess because I have no kids, I don't see the need to jam that many humans into a metal container in close proximity to one another. If I wanted that sort of misery I'd buy an airline ticket and fly somewhere.