I agree that it's bullshit. I don't need a big rock on my hand to show off to everyone. When we got married 40 years ago, a modest diamond was all my husband could afford and that was fine with me!
In fact, we decided that in lieu of a big expensive wedding - that we would just take the cash. We furnished our first house with that!
If you have to impress - get a big cubic zirconia - a lot of jewelers have trouble telling the difference between that and a real diamond. You ever hear of blood diamonds? The De Beers family are pretty evil, really.