It is a way of pointing out that hardly anybody uses Monero for anything other than crime.

How do you know that? And even if it was true, what is the underlying point? I don't see the "hardly anybody uses Monero for anything other than crime (right now)" -> "cryptocurrency is useless" argument working.

It's not exactly a secret, is it. Come on, you're not that naïve.

I feel like my point is getting ignored and I dislike this type of reasoning via "common sense, obvious, irrefutable narrative".

I don't see much of a point other than "I don't want to believe this because it makes Monero look bad".

The point is people have a right to financial privacy and cryptocurrencies are one possible way of achieving this. Therefore, cryptocurrencies are not a priori useless.

I'm not even talking about Monero or the particularities of its current dominant usage as I think this is irrelevant for the above point.

They are indeed very useful to criminals.