Yeah, at best Bitcoin is pseudonymous (through mixing or obfuscating through exchanges). But really, what person committing tax fraud or other underground activity wouldn't just use an actual privacy focused crypto such as Monero (as you said)?

When reading articles like this I substitute "Bitcoin" for "Cryptocurrency" and it makes more sense. The public has just recently normalized Bitcoin and so that's what they write about. Give it a year or so and they'll catch on.