This perfectly normal behavior really seems to bother you for some reason. I have no idea why you feel it's one person's obligation to ask all those around them if they have any special needs instead of expecting those that have a request to simply ask politely.
Where in the world would you draw the line for that sort of expectation? There are endless hypothetical scenarios where you could go around asking people if they need something. Maybe the next time I use the bathroom in my office I'll send a mass email to the whole company first offering them a chance to use it before me, just in case. After all, it would be rude and selfish to inconvenience them and make them wait for me to finish first. Perhaps I should offer every stranger I see on the street some money just in case they need it, instead of waiting for someone in need such as a homeless person to approach me and ask for help.
Just because all of the sheeple on the plane rush to their feet the second the seat belt sign turns off (aka the all rise chime as I've heard flight attendants call it, a way of poking fun at these people) doesn't make it normal, or the polite way to depart a plane. In fact I'd consider it the rude way to depart because most of those people that congregate in the aisle tend to push, shove, bump into and invade the personal space of everyone around them just so they can save 30 seconds in getting off the plane or to their bag in the overhead. I'd rather just avoid being pushed and crowded, so I'll wait patiently in my seat to depart thank you very much.
So many of your generalizations are incorrect. I've been a frequent business flyer, and your generalizations are way off base for every frequent flyer I know. Smart travellers pack light and carry on their luggage whenever possible. Then there's no risk of lost baggage and it forces you to pack light and leave the useless crap that most people travel with at home. I have no issues with my personal health that is preventing me from standing. I'd think an able-bodied person would rather stand than sit if given the choice, the wiser option seems to be to relax and take a load off. I am perfectly capable of sitting in the aisle and not getting bumped by carts and people all flight because I'm not some obese person spilling into the aisle, and like any good traveler I keep my arms and legs out of the aisle and out of other people's way.
I look forward to continuing to book aisle seats and patiently sitting until it's my turn to depart on every future flight that I take.