While i doubt it's profitable, there's 0.003% coordinator fee.
According to Chainalysis, Wasabi mixed $250,000,000 in 2019*. That means $750,000 has been paid in coordinator fees, which seems pretty profitably to me .
$250 million times 0.003% is $7500. OTOH the 0.003% fee is per anonymity set and Wasabi uses 50+ sets by default, so it's a 0.15% minimum total fee, usually higher. $400-500k would be a more reasonable estimate, but that's just the revenue. There are costs/expenses for sure.
At any rate, I'd say nopara73 claiming that he makes money is good enough to assume there is profit, and I'm sure he could pay for a signature if he wanted to, and I'm quite sure he's not paying for Gyrsur's copypasta signature.