Media outlets attempt to explain these holidays that go unnoticed outside of church and synagogue:
Pentecost is this Sunday. What the Heck is Pentecost? From PBS.org
Field Study: Why Shavuot is all but ignored across America From Tablet
According to Marissa Brostoff's piece in Tablet:
“The holidays that have done really well here are either firmly grounded in the home or allow for a kind of interplay between the synagogue and the home,” says Jenna Weissman Joselit, who teaches American Jewish history at George Washington University. Home-based holidays have strong elements of material and ritual—seders for Passover, sukkahs for Sukkot, menorahs for Hanukkah. But on Shavuot, “there’s no stuff and nothing to do, if you don’t go to shul. ”
But what about the cheesecake??