It's interesting that you put that quote forward as a reason to support UBI. I have the opposite reaction: I have no desire to be taxed to feed people "scratching their creative itches".
Yeah, I understand that. Took me a while to get past it too.
What helped was the realisation that almost all of the history of Science is made up of wealthy individuals scratching their creative itches. Art and Music less so, because patronage was a common method of funding that, but we lost out on a huge amount of both because patronage was rare. Imagine what we will discover, what vast wealth of new knowledge and talent we will enjoy, if we can free up those who can make a genuine contribution from having to pay rent? (and yes, 90% of everything is shit, but the 10% makes up for it).
Also, I changed my "scarcity" mindset. I enjoy what I do, and get paid enough to do it. Paying taxes is part of that. I resent the various governments I've paid taxes to for wasting my money in all sorts of ludicrous ways, including the vast subsidies to wealthy people and industries I flat disagree with. Paying my tax money to actual people seems like a great deal to me :)
I'd agree with you if it actually helped artists find their artistic stride - there is definitely artistic merit in forced constraints. But it doesn't; it forces them to commercialise to pay rent. To make what is commercially appealing (or appealing to a patron) rather than what they actually want to make.
And I totally agree with the argument that commercial appeal == value, and artists don't automatically deserve a living. The whole "Spotify should pay us more because we can't live on what they pay us" argument leaves me cold. But I think that's a different discussion. If you are going to force artists to commercialise then that argument applies, and artists must adapt their art to commercial reality, or starve, like everyone else. However that's not the same discussion as "if we paid everyone a basic income, I wonder what amazing art would be created?". Different starting premise.
is it really a benefit? seems to me like it inevitably leads to optimizing for earning money rather than helping people, leading to a lack of focus on solving problems which affect people but aren't profitable to solve (focusing more on a perspective of scientific research rather than art)
The question is not really if you want to be taxed to pay for UBI, but if you rather want to be taxed to pay for UBI than some other bullshit that you are currently being taxed for (of which there is a lot).
