Hmmm, not sure if you realize that bcash is already horribly centralized. This is what we’re trying to avoid with bitcoin. 

Also, there is no risk to OP_CAT on Liquid because it doesn’t have mining like bitcoin. 

The problem with enabling OP_CAT on the bitcoin timechain is that it can create arbitrage opportunities which can encourage miner centralization. 

Here’s how:

CAT can enable on chain atomic swaps. 

https://bitcoin-takeover.com/andrew-poelstra-bitcoin-covenants-op_cat-vs-op_ctv/

On chain atomic swaps can be used to create securities marketplaces (eg Uniswap on Ethereum)

https://www.gemini.com/cryptopedia/what-is-an-atomic-swap-token-swap

Unswap-like exchanges create the potential for centralizing MEV by allowing speculators to bribe miners to reorder transactions so the speculators can jump the queue. 

https://medium.com/flashbots/frontrunning-the-mev-crisis-40629a613752

Smart contracts, arbitrary code execution, etc are fine if they’re off-chain. But if when they are used on-chain, then the they can harm bitcoin’s decentralization. 

Devs who want to use OP_CAT should just use it on Liquid. No need to take unnecessary risks with bitcoin.