Why does there have to be a "what if"? What if someone is lying about being injured, what if the stroller is full of crap from the parks, what if the child isn't sleeping but could stand themselves. As a society we're so worried about justifying our actions because of what others are doing or not doing. How about if you're physically capable just let someone else sit. Man or woman. Young or old. No you don't have to at all but if you're feeling up to it spread a little kindness. After all, the guy with the stroller full of park souvenirs that you think needs to unfold i or put his kid in it, spent 300 dollars on his tantrum throwing kid who refuses to walk when his feet hurt just as bad as everyone else's. Or he just had a really good day. Don't worry about his stroller or his bags. I'm just saying stop worrying about everyone else and do what you can and what you feel to be right and kind.