The Ick Factor
The real problem with pink slime is the "Ick Factor" - it looks and sounds gross.
Part of the psychology behind the Ick Factor is labeling. The language we use when we identify things influences how we interpret them. As Shakespeare wrote, "A rose by any other name would smell as sweet."
We can call an old car "used" or "pre-owned;" we can call civilians killed in wartime "men, women and children" or "regrettable collateral damage." And we can call processed beef parts "pink slime" or "boneless lean beef trimmings."
It's only in recent years that psychologists have taken a serious look at what disgusts us.
Pink slime may not be appetizing, but it's not much more disgusting than what's in all-American hot dogs - you don't want to know what kind of "miscellaneous parts" go into those ballpark favorites.
Many people would be disgusted at the idea of eating another animal's skin and dermal fat - but they happily munch down pork rinds (made from fried skin), and leave the skin on cooked chicken and turkey.