I'll have to admit, if i were to fly and had a "customer of size" seated next to me and they were "spilling over onto me" i'd be pissed. I'd bitch and moan, under my breath, and i'd tell the story to all my friends about how aweful it was.
But...
After about 2 days of remembering it and telling everyone, i'd casually forget about it. It wouldn't have ruined my week and it certainly wouldn't have dramatically altered the grand scheme of my life. And if that plane ride were so uncomfortable to the point that i wanted to make extra special certain that i never have even the remotest possiblity of being seated next to a person of size, i'd fly first class.
Seriously now, who hasn't stood in line next to someone who reeks of garlic, or sat beside someone at a public venue that smells like spilled beer and stale cigarettes? It happens to everyone, but we've all forgotten about it in a relatively short amount of time when looking at the big picture of our lives.
It's not a big deal, no pun intended.
Now i realize that content of my little rant wasn't the point of this thread, but it's my .02