Reading the article, I would say its more of comparing unrelated items and from that trying to make one looks good more than the other. Visa is a payment company just like MasterCard or PayPal that enables people to have access to their money for those who relies on the debit cards as against the credit cards which you are allowed to spend more than what you have.
Cryptocurrency on the other hand is not just one company but series of coins being valued. Now comparing a ton of coins with a company and saying one is better off, is just an uninformed conclusion if you ask me.
Your primary point is correct. Is BTC still at least 50% of "total coin caps"? If so, then the article is somewhat valid since the top coins are showing signs of becoming truly huge.