Sure, but you could say the same thing for teachers, foodservice workers, nurses, etc.... yet they are unable to avail of this program, for reasons I don't understand.
It's a cultural norm. Extending it to other generally penniless artists is too.
When universities in other countries start running courses on Irish food service workers we can reasonably expect them to be included.
These are mostly employed positions, where employees have procedures to negotiate their salary with the employer (which might be the government itself).
Most artists otoh are self-employed, and the government decided that the country at large would benefit from giving some of them economic support. You can argue with the modalities but the reasoning does not seem that opaque to me.
How is that different than being an “artist” whose art isn’t consumed by anyone willing to pay for it.
I kind of see the reasoning to some extent but then also e.g. “full time gardeners” if their yards are visible from the sidewalk should be paid.