No one surrendered anything. Must you see dragons around every corner? They have meds for paranoia, you know.
Let's see. Chanukah and Christmas are both in December. So, you insist on melding the party held that month into a "Holiday Party."
Labor Day and Rosh Hashanah are both in September. Have you attended "Holiday Parties" in that month too? Or were there parties/picnics entitled: "Labor Day," and were there parties entitled "Rosh Hashanah."
There are ten federal holidays on the Calendar, and Christmas is the only one that PC-revisionists refuse to call by its proper name.