Whilst crypto maximalists can be annoying, there's also anti-crypto maximalists such as the source you're linking to.
It is legitimate to raise the Tether concern yet he confidently drops into very binary conclusions driven by his pure hate for crypto.
For example, his claim that it's 100% a scam whilst this fact isn't established.
Or calling any trade in crypto "shady". This one shows his true colors. A huge amount of people just deposit dollars on a KYC exchange, then buy and sell whatever crypto they fancy.
None of this is shady. It's fully legal, taxes are paid, it's like stocks. Yet according to him, any trade in crypto is shady.
Or, the claim that the 800 billion market cap of Bitcoin is solely based on Tether. That's an absurd statement.
As said, maximalists can be extreme, but so can anti-maximalists. He deeply hates any and all crypto, has zero nuance, and is not open to any type of discussion.