It's not that white people have no culture,

It's that everything that originated from a predominantly white cultures get labeled either as "colonizer culture" or as a "white supremacist dogwhistle."

Also, if anyone claims that something is a "white culture thing," then suddenly they're racist.

If you don't believe me, just show up to a multiculturalism group and try to celebrate Irish culture or mention being proud of your irish heritage. They'll assume that makes you a white supremacist and chase you out.