Earlier quoted context omitted.
You can read more here when it was posted previously: https://news.ycombinator.com/item?id=29366310 Basically he built up a strawman and then burned it to the ground.
I’m scouring through the comment chain but I’m not really finding such a definitive response. I’m assuming you’re referring to the first chain of comments, but that seems to boil down to “the attack exists but it’s fine because to successfully attack the network would destroy the network, and with it any profit you’ve made in the attack; thus you cannot profit” — but this is directly addressed by the “nothing at stak…
If you’re still worried about that happening to some ETH you received, wait for the blocks to finalize. Once they have, they will never be reverted without a change to the protocol.