> Yes, but then they are not offering a ride that is better than a ride in a private car.
Oh, I missed that point. I mean, personally I'd say that any bus offers a better ride than driving a car, in that you do not have to _drive_ the thing, but tastes differ, of course.
Ideally most urban bus routes would be short enough that healthy people can comfortably use them without sitting.
Realistically, the costs of operating a bus are pretty fixed, and bus networks have hard space-based caps on capacity (as I mention elsewhere stops in particular are a problem), so the priority will always be on getting as many people in the space as possible. It's hard to see why any public transport authority would do seating-only urban buses; it would degrade the system as a whole, and the ticket price would be unreasonably high.
Most people, also, will care more about "can I actually get on the bus for my 20 minute journey" than "if I get on, will I have a comfy seat", which tends to indicate a mostly-standing design with seating available for elderly and disabled people.
As an example, take my local system. Dublin's main bus system has about 1,300 buses in operation; almost all of these are double-deckers with a capacity of 90-100 people. The system is pretty much limited by availability of drivers. Fares are 2 euro for a 90 minute journey (or where the last leg of the journey is started within 90 minutes of the first one). Adopting your system, we'd need five times as many buses, so for a start we'd need 6,500 buses, along with maybe 15,000 drivers and another 5,000 or so support staff. It's hard to see how that could happen without dramatically increasing the cost. But also, at peak times, major bus corridors are full of buses, and major bus stops have buses queueing up. It would simply not be reasonable to 5x this.