פירוש על קידושין 141:4

According to this source, the lineage of Eretz Yisrael is dough, meaning mixed up, in comparison to Babylonia. Babylonia has preserved their lineage better than Eretz Yisrael. The practical ramification of this is that a family from a place of better lineage would have to investigate the lineage of someone they want to marry from a place of poorer lineage.
There was an attempt, according to this source, to change this around. But it failed. Even those in Eretz Yisrael realize that the lineage of those in Babylonia is superior.
We should realize that this is a source in the Bavli portraying those in Eretz Yisrael as admitting that those in Babylonia have superior lineage. From a source like this, it is not possible to know what those in Eretz Yisrael thought about their lineage.