You've emphasized this point more than once, but I don't think it's a good counterargument to the GP. It is equally valid to say that they have explicitly (voluntarily, knowlingly) chosen to accept donations for their work.
By profiting off their work and not supporting them you are making your own choice. It says nothing about the authors' preference.
They chose a license that is _explicitly designed_ to allow people to profit from their work without paying.
There are many other licensing terms in common use. They chose that one.
That's fine, they can do what they like with their work. There is no moral obligation to reinterpret their motives in a fashion that differs from their formally expressed preferences.
They chose to accept donations -- also fine. If you want to donate, go ahead. If you don't -- that's fine too, by definition.
By profiting off their work and not supporting them you are making your own choice. It says nothing about the authors' preference.