The stereotype tends to go:

-- Gen X doesn't care what other generations think of them.

-- Gen Y cares too much about what other generations think of them.

This may sometimes create philosophical and social tensions between Xers and Millennials (depending on how closely the individuals adhere to the stereotypes, of course).

If you're asking about my personal belief: I don't buy into the stereotypes themselves. The patterns may be there, and those patterns may form trends. But the patterns/trends shouldn't define any one generation as a whole. They can be used as markers, but they shouldn't be assumed to be the norm.