I love that you asked this question, although, of course, you didn't actually phrase it as a question, because this quote is literally in the book. I addressed this particular misconception as it relates specifically to Costco, because I myself once fell victim to the same misconception.
If you think Costco has endured only because of leadership, because of its strong ethos and its immense size, because you think it's just too big for Wall Street to mess with, you are not correct. My friend, nothing is too big for Wall Street to mess with. Wall Street has tried many times to dismantle Costco's ethos, and every time the unique structure of Costco is what has allowed them to resist.
The parent comment didn’t say anything about size or wall street. It said leadership is what has preserved it.
Which it doesn’t seem you have refuted in any meaningful way. You just restated what the parent comment is responding to with no further reasoning as to why leadership doesn’t account for it.