I think diamonds get a bad rep because of shitty companies like De Beers who artificially pump up the price of diamonds. I don't think anyone would have an issue with diamonds if their price range was comparable to amethyst and made ethically.
Yup. We got diamonds for my wife's ring, but we paid a reasonable amount (<$1k; pretty small but pretty diamonds) and we were told they were ethically sourced. I hope that's true, but we're only a small part of the problem, if at all.
Most of my wife's jewelry is her birth stone, which is way cheaper and doesn't have the ethical issues diamonds have.