I'm grumpy today, so maybe this will come off as overly harsh.
This reads as an incredibly lazy article to me. Vanguard has a HUGE price advantage because it has no outside shareholders and the author glosses over that as some kind of "company culture" phenomenon. There are no incentives for it to charge high fees. It runs everything at cost, so the company's prices are completely sustainable as well as always dropping. You can always be sure you're getting pretty darn close to the best deal on every fund Vanguard runs.
If price were the sole reason for success, then Econ 101 tells us that competitors would have simply cut their fees in order to recapture lost market share.
They can't, because they have to make money somehow for their outside investors.
There are no citations of prices for either Vanguard or it's competitors, so we have no idea how the author could come to the conclusion that
...we must conclude [Vanguard's popularity] is much more than merely price-driven.
Only the first reason listed actually matters (and as I mentioned above, the author emphasizes this far less than he should). My understanding of history is Bogle chose to use an index fund because it would be the cheapest, not the other way around (someone please correct me if I'm wrong). His saying has always been "costs matter", not "indexing is the best". This means the next two follow directly from the first one, and the last "feature" of the company is a nonsense reason.
Another quote that stands out to me:
[Vanguard] missed the move into factor investing, sometime known as smart beta...
Did it? Vanguard has a ton of funds aimed at different factors and has a minimum volatility fund. Maybe they were late to this world, but saying they "missed" seems wrong.
Vanguard is a great company to put your investments into, maybe even the best, but this author doesn't understand why.