I think it's fair to say that younger people are less motivated by money than their parents were, but I also think it's fair to say that younger people have access to a lot less of it and thus, have settled on rewards and social signals that are easier to come by.

David Graeber made the point in Debt: The First 5,000 years that money is the means of exchange created for trade between people who didn't trust each other, and that its first applications were slavery and blood debt. That said, you can probably count on one hand the number of people you trust but you can exchange goods and services with nearly anyone on the planet so it's not like the stuff doesn't have its uses.

Money isn't so much a thing as it is a measurement, like speed or weight. Dimensions can't be good or bad, they can only be relative. You'll be interested to know that money is only a motivator up to a point, or at least that's what all the en vogue social science says. Beyond about $72k a year or the equivalent it just becomes a high score to compare yourself to your friends.