Honestly, because diamonds are just cliché, over priced and over made meaning that don’t have a real high value and all the other gemstones have gone so unloved over the years. I mean, as a 28 year old man I fucking love my emerald earrings. Ruby ones as well for that matter. Fuck diamonds my dudes puts some color in the bling.
I am wearing opal right now. Diamond are just kind of meh.
As someone who uses both. I think Mastodon also just doesn’t have the users, it is not as easy to setup and I think understanding instances and its UI are less user friendly.