Bitcoin can already be used for NFTs and other tokens (using protocols like Counterparty, Omni, OpenAssets, Taro, etc). So while I understand why people want to try to restrict use of the blockchain to be only for BTC ecash use cases I think it would be unfair to oppose some new protocol that enables doing a lot of useful new things with BTC and also happens to allow creating and transferring other digital assets. It might even be impossible to come up with a protocol that can be used with BTC but no other digital assets (or maybe it is possible, but the tradeoffs are too restrictive even for their liking; in any case, if it were possible, I would think that the BTC-only people would have proposed it by now).