What don't they ruin? They can literally take the most exciting activity, and just by them being present I no longer want to join in. For instance, I love waterparks. I don't even go to certain ones anymore due to the insane number of hams in two-pieces, not to mention the fact that the water attractions are probably the closest they have come to a shower in months. Fucking fats should be banned from places because they suck the fun right out of everything.