The "knee turn"

So I’m getting off the always crowded #16 Arbutus bus after work yesterday, and I get the always perplexing “knee turn”. For those of you without public transit experience, the knee turn is a situation in which you are sitting next to the window, and you turn to the person sitting next to you to politely inform them of your impending stop, at which point they do not get up to let you out; rather they turn their knees away from you, leaving you to suck in your gut and decide (to quote Brad Pitt in Fight Club) whether to give them the crotch or the ass as you slide by. Am I alone when I say, what the hell is this about? Most people (obviously myself included) manage to stand up, move aside, and allow the exiting party, baggage in tow, to sail past unmolested. In this particular instance I had my (fashionably) large purse and my lunch bag in one hand and, due to the severe angle at which I had to contort my body in an effort to extricate myself from this veritable jungle of limbs, seating and handrails, I managed to inadvertently smack the offender in the back of the head. Needless to say I did not apologize. Michael later asked “how old was this woman?” and I replied that she seemed to be in her late forties or early fifties. His pursed mouth and pained expression led me to believe that I should acquiesce to this woman’s knee turning rationale, because she wasn’t some slack-jawed, gum-chewing juvenile. Either that or his expression meant he had a BM coming. I, on the other hand, believe that her age would have led her to know better, and to practice “do unto others” etiquette.
There are other actions lacking courtesy that I witness periodically on my journey from the downtown core to my happy little ‘hood. The all too familiar situation of young, able bodies taking up seats designated for seniors and the disabled. There are the puzzling individuals who sit next to an empty window seat; clearly introverted and misanthropic riders, clinging to the vain hope that, during the rush hour swell, no one will inquire as to the availability of the seat next to them. Additionally there are the mentally defective that neglect to shed their backpacks, continually and obliviously butting it against other patrons, while engaging in jocular banter with their friends.
To bring this particular castigation to a close, I would kindly petition you to avoid the knee turn when letting someone off the bus… lest you get slapped in the back of the head.