Truth is that when you are stuck in bumper to bumper traffic, stopping and starting, manuals are tedious and not a good experience.
I have what's regarded as the best manual transmission in production on my Porsche, but in traffic, the automatic transmission on my econobox Mazda3 still does a better job moving the car from a stop smoothly with minimal impact on fuel economy with almost zero effort. On the Porsche, I'm either slipping the clutch causing more wear or having very jerky/abrupt starts, revving a bit more than necessary or risking stalling/bogging by short shifting.
Sure, the manual is a lot more fun and engaging to drive, but most people are simply content with commuting with an appliance.
I haven't actually seen a car without a sequential/manual mode for a long time, come to think of it. Used to drive a 2003 Grand Caravan that didn't have it, but it had a few different automatic modes that helped fill that void for hills.