It's hard to know what this looks like.

Nearly every person I've met struggles with empathizing with people who aren't in their in-group, that's not a homeschooled-specific thing. The enormous polarization in the modern political climate is due to precisely the kind of insularism that you're calling out, and it's not because of the 1.5% of the adult population that was homeschooled.

Considering how many people choose to be republicans and democrat's I don't think this is a home school issue.

In many public schools you have the exact same thing depending on where you are.

There are also a lot of adults who show the lack of meeting a diverse set of homeschool families as well. They don't usually see that in themselves either.