Maybe this is just my thoughts but because anyone can leave at any time in a ring game, that can affect some decisions. In a tourney you know you have so many people and they all want to get to the money. If you sit at a table and everyone has 10 bucks, some goals may be just win 1 dollar and leave or double stack and leave or just play for an hour. I waste time at penny games sometimes so I could assume someone with a much bigger roll, or just better paying job, would do the same thing at a bigger blind table.
That could affect different people in different ways. but I know if I sit at a ring with 10, I get to 15, and sometimes (depending on how i'm playing, others are playing, and cards i'm getting) I want to leave. Sitting at a sng with a 10 buying and I win a similar ratio, I don't have the choice of leaving and I know even though I have 3 stacks, I have to survive.
Sorry about the rambling but I guess since tourney is survival and goals are obvious makes it different from rings, where you just want to make a profit, even with just 1 big hand.