In the current context of ethnic division, how significant are ethnical celebrations in a foreign land?

I have a Gurung friend who always goes to parties with those gurung white silk scarfs and puts it on the party hosts. I don't know what he is thinking but isn't it kind of odd to force your own culture on others who are not from your own ethnic background? It is probably not a huge deal but I find it odd that gurungs are the only ethnicity that I have seen do such things.

I have nothing against the gurung folks but I find it interesting that they are always into promoting their own culture. They have a very good network among themselves. It's good in a way but sometimes I feel like they put their own ethnicity before their Nepali identity which is a little concerning in todays Nepal with significant issues related to national identity versus ethnic identity.