Here's the solution to the obese passenger dilemma:
Ask yourself: what are the odds that you will be forced to sit next to someone so obese that they occupy more than one seat on your next flight? Would you bet money that your next flight will be next to an obese passenger?
If the answer is no, and you somehow get put into that position, the solution is to bite your tongue, quit feeling sorry for yourself, and remind yourself that you get to experience the miracle of flight and you get to soar through the heavens at 500 mph to get across the country in less than a day. Imagine [bleep]ing about this to your ancestors who had to go on these grueling expeditions for months at a time, and half of their friends and family died along the way! Lol they'd probably be like, "Ok so you're telling me you had to be uncomfortable for a few hours and now your life has been ruined? Gotcha."
If the answer is yes, then you arrange your flight in such a way that you minimize the odds of that happening. You use a different company that allows you to choose your seat or you get out of economy. This is where you say, "What?! But I shouldn't have to do that! That's not fair!" Tough shit. You do have to do that. And it's really not that big of a deal.