That is window-middle-aisle boarding, sometimes called WILMA, and used by United for a while.

I prefer nickel and diming, because often I find myself not needing to pay for services I don't want or particularly care about.

I agree with you to some extent (e.g. charging extra for food that many people don't really want is good), but both preferred seating and, to an even greater extent, paid luggage impact everyone on the plane.

Not really.

The people who don't check luggage and sit in the non-preferred seats aren't impacted by the fees.

Probably more importantly to the airline, the airline's status customers get free checked bags and seat selection which adds value to having status. That adds an incentive to maintain status so as to avoid those fees. The preferred, exit, and extra legroom fees also holds those seats open longer so status passengers will be able to select them (for free) closer to departure time.

I usually fly on airlines that don't play either of these games (well some preferred seating, but none of this cabin carving stuff). There is always extra space in overhead bins because anyone who doesn't feel like dragging their bags through the airport can check them. There also isn't much seat shuffling or ensuing drama. This benefits ALL passengers.

This is true in my case. Booking directly into PC is my favorite perk of reaching 75K and will probably cause me to fly a bit more on AS than I would have otherwise. To me with AS either MVP or 75K is what I go for. Gold benefits are kind of "ho-hum". Sure, better chance on the upgrade list and booking into PC a few days before take-off but base MVP gets me into exit rows and elite check-in which are both VERY nice. The lounge passes and 50K bonus miles with 75K are also really nice. This was looking like a light travel year but some life changes have just made it to where I will be flying a lot and should reach 75K easily.... we'll see about 100K.