In terms of the substance - bottom line they have taken something without permission and sold it on. Sure - they have added value in the process - but if I steal your car and mash it up with another one before selling it on - it's still theft.
The original post was implying there was no harm as a result because it's just copying - the original owner was not deprived of anything.
My point was they are potentially being deprived of a living - and that's through stuff being taken without permission - not through fair competition.
What matters here is not the semnatics of theft or copyright or whatever - what matters is fairness - and I accept that's a judgement.
I don't see a problem with these companies having to either pay to incorporate material into their models or/and the authors having the right to refuse to license.
Note - that's not to stand in the way of the development of these tools, but to ensure that the effort that went in to creating them ( which includes the generation of the source material ) is properly rewarded.
If OpenAI etc al think creation is a trivial part and it doesn't need rewarding - they are free to bootstrap their models by creating all the inputs from scratch.