In fact, that point I mentioned right in the OP, which you included in your quote, by the way. I highlighted that we are not invulnerable or immune to the impact that a big whale could easily deliver. But then the price would plunge however low, even to single digits if, for example, Satoshi himself comes out of his hideout and drops his stash of coins on our heads. But there are more than enough bearwhales beside him who can dump the price below what we could reasonably think of.
The Mt gox coins were never written off but the Satashi coins after this period of time are considered out of circulation permantly. So any return of the OG would be both surprising, no doubt welcomed but very much introduce a giant source of coins back into the market which would not be bullish.
Satoshi is not the only one with a huge stash of coins. I've read somewhere around here that there are a few guys roaming in the wild who have more than 100k bitcoins in the wallets. What if one of them decides to cash out one day? Before the Mt. Gox dude, it was all theory and speculation, but now it is no longer the case. It is a new reality, a reality where one whale crashes the price dozens of percentages in a matter of days. Surely not something to discard or write off in your investment decisions.