Here's my guess. Ethereum salesmen said that Bitcoin is old tech and cant do things Ethereum can. Bitcoiners, said the stuff Ethereum does (like tokens and NFTs) are stupid. Now Bitcoiners don't like innovations that are considered "shitcoiny."

It's not the best of reasons, but it's my best guess of what happened. Of course I know that BTC already had Omni and Counterparty. But this was before alot of people's introduction to the space. Also remember the earlier adopters were more often technical than those who arrived in the 2017 bull market, or later. The less technical people were, the more likely they could end up being bizarely opposed to certain (well in-demand) use cases due to Twitter narrative battling. Highly respected Bitcoin devs were involved in the birth of RGB, early research by Peter Todd, and envisioned by Giacomo Zucco in 2016 (a little before the ICO craze really took off.) I'm not sure how much either are still working on it. DIBA, a digital bitcoin art platform presented at Bitcoin 2021, though is still in Beta (and on testnet)

For what it's worth, I've seen it come up alot after the announcement of Taro by Lightning Labs at Bitcoin 2022. Some people have called it copypasta of RGB; (#19422) or at least they shoulda given RGB a shout out.

I'm not smart enough to know if RGB or Taro is better, but I do know Lightning Labs has some funding behind it. And Stacks has that sweet premine money. So yeah, we will see I guess.