This branch of the thread started with someone asking me to name some specific attack vectors which led to me being a Segwit skeptic. You don't seem to think they are significant. I think they may very well be fatal at some future date. Now we understand each other.
Peace out.
I can't think of 51% where an attacker can to extract a large amount of real value. All they end up doing is destroying/severely damaging Bitcoin.
Now you could profit by shorting BTC, but there is no difference, whether its Segwit or Non-Segwit the outcome is the same.
Can you give me a scenario where a Segwit 51% attack actually allows the attacker to profit.
A 51% attack will require a >=6 block re-org, and if there is ever an unexpected >=5 block re-org, BTC (& fiat on exchanges) will basically freeze until an agreement on how to handle the attack.