Ah, just like Easter, Christmas, Ramadan, Fat Tuesday, Valentine's Day, Purim, Holi, Passover, Cinco De Mayo, D-Day, etc. etc. etc.
Observances regularly don't give you a clue what they are about. Like, if you weren't already aware about Martin Luther King, Jr. day, you'd have to Google it to know what's up. Same with Rosh Hashana. Or Eid. I think you might be getting stuck on something that is demonstrably not a unique phenomena and it's reading a little like there's something about Juneteenth itself that's bothering you.
Observances regularly don't give you a clue what they are about. Like, if you weren't already aware about Martin Luther King, Jr. day, you'd have to Google it to know what's up. Same with Rosh Hashana. Or Eid. I think you might be getting stuck on something that is demonstrably not a unique phenomena and it's reading a little like there's something about Juneteenth itself that's bothering you.