Allowing outsourcing was the morally only correct thing to do. Otherwise the craftsmen would have been doomed to eternal servitude to their art. An artists signature on a work is not a guarantee the artist vouches for working on it only themselves. It's a guarantee the artists vouches for the quality of the product. So an artist signature is more of a form of branding than a signed proof of n units of work by person x.

Lots of great artists have outsourced the commoditiziable components of their work.

If you look at craft people, the ones who try to toil alone making articles that are not thousand euro a piece luxury items you wish they would know how to leverage outsourcing so they could focus on what makes their product unique and not just a batch of labour.