They do. You probably haven't noticed. The once who love sex and are really gullible, and believe in tall stories, end up with French speaking Africans, while others end up with the others in your list.
It was first proposed about 20 yrs ago by Samark's administration, but was never implemented. And I believe it was also proposed by the previous governor, but was also shelved.
Same experience on Qatar Airways, plus about 4 inches of leg space was obstructed by the seat in front. From my observation, the middle seat was the most comfortable seat on that particular airplane.
They do it at home everyday. At least, in the States, it's a major issue for retailers, and they are mostly not confronted by staff for fear of being attacked, or because they've not incentive to do so.