>So the world is filled with gold-diggers? No. Not true.

Wanting a mate who is financially secure doesn't make a woman a gold digger. It's no different than the vast majority of men who want a physically attractive mate.

>You'll find it shocking that in some parts of the world people are happily married without any jewelry at all.

Yes, different cultures have different standards (and there are outliers within cultures). In some places a herd of goats functions as a status symbol, in the US a diamond serves this function.

That doesn't mean that every woman here absolutely requires a man who can buy her a diamond, but the majority do.