The number is probably higher for the elite, most renowned artists, and it might well benefit society to ensure a portion of the best can live of it, but in many places that is already hard enough that a substantial portion of the ability of even elite artists to live off their art often comes down to government funding and grants, followed by patronage that is more about status than ability to commercially exploit a work.
That's not to agree with the notion that real artists can't want money too, because I don't agree with that, but I also don't agree that most artists have made art for gain.
At least not as a primary motivator, as if gain was the main goal, it's usually a bad one (e.g. the average full time UK novelist earns below minimum wage from their writing)
There will have been very few serious artists in history who could afford to do it for the love, because art materials cost money, and time making non-functional art is time not earning enough or working enough to live.
Art as a pastime is a very modern invention, surely. That is
But even before that I'm not convinced that about your claim. I'll concede that most artists whose works have survived for a period will have done so for patronage, because others will have face severe limits on production. E.g. Haydn being able to be a court musician for the Esterhazy's ensured his work was played in front of an audience and associated with status, and so secured it distribution that someone composing and playing in less privileged positions did not enjoy. For large parts of time we can expect most art to have gotten lost because it was not written down and recorded, or because it was produced or kept in ways that hampered its longevity.
E.g. already under the Chinese Tang dynasty we know that art was seen as an acceptable pastime and that while patronage happened, it was not a particularly desirable job, to the point that one of the earliest known Chinese painter was by a man - Yan Liben - who apparently became ashamed when he was referred to as "the imperial painter" and warned his son not learn to paint to avoid his fate of being known for it, because it was lower status than his actual paying job, and one he at one point was ridiculed for.
People draw or make music or create stories whether or not we get paid for it, and even in situations where it's seen in a negative light.
Fair. But the argument I am responding to implies that making money is antithetical to making art — that artists can’t think about making money if they want to make true art. This is, frankly, patronising bullshit in the fullest sense (not least because it denigrates artisanship in the sense of making truly artistic useful objects).
Arguing for a world where artists should not be respected if they are as focused on their income as anyone else is insulting, not least when great art makes such huge sums and generates independent wealth for its owners once it becomes an asset.
It belittles art itself, as a plaything or an alternative to real work.
People who are less excited or connected to the coal face of technology are not necessarily ignorant or engaging in motivated reasoning if they question an innovation.
It is a bold strategy to suggest that Nick Cave is confused by ideas of income and art. I don't care who you are: on this topic, Cave is almost 100% certainly better informed than you (or me).