Ethnic identities are important. it's good you didn't ask, because it's inappropriate to go into this subject with people unless you're invited to do so by them first, but it's not because ethnic identities are not important. That they "didn't seem important" to you reflects that you do not understand how a person's ethnic identity shapes their experience of the world, and that suggests you are perhaps unaware of the privileges your whiteness has granted you.
This is so simple to understand, yet you missed it completely, and then dismissed it with this statement. Poor form.