I'm with you. I've seen such crass behavior at the weddings of so-called educated people in the past 20 years or so. It's sad. Don't get me started on the creative "own vows" and "dancing down the aisles on YouTube" antics in churches, and the boozy receptions.
People have lost all sense of it being a rite of passage to adult responsibility, honoring God by sanctifying an intimate partnership, a joining of two lives, preparing stability for future children, or expressing solidarity with the elders who nurtured them to this point. It's become about impressing their friends, not continuity with religion or their families.
I am in total agreement. Bad enough my daughter and son inlaw were married by a judge (they are not church goers), It was appalling that her friends did not give wedding gifts to the bride and groom. That was inexcusable.