Arrogance? No need to be so mean-spirited about your fellow humans.
Here's my take:
The difference is that the AI is taking actual work that artists created. As of now, copyright protects creative works so that is illegal. From what you wrote, it sounds like you misunderstand this issue. I know it's an easier conversation to have when you make this a simple black and white issue with a clear enemy (in this case the "arrogant artists" as you called them are the problem). But let's clarify a few things.
1. The technology is not the problem
Photoshop is a good example to explain this point. Photoshop is also a program (it is technology) that took on some of the workflow of photographers/digital artists. When it first came out, it was also lauded as "the end" for artists (so was the camera). Photoshop is simply a tool and it is a tool used by artists to save time.
2. AI is breaking the (current) law.
The digital art created by Midjourney (and the like) can often still be recognized as being made by the original artists (sometimes even retaining the signature/watermark). AI programs are breaking copyright laws because the image is still recognizable as the original (the original image is protected under copyright law). It is also why there are several important court cases pending on this topic.
3. AI does not create good art (yet) without artists (professional/semi-professional).
I can ride a bicycle, but I'm not a professional cyclist. I could not compete in the tour de France. It's really easy to throw around the phrase "art is subjective" because it is part of human expression, but once you get beyond hobby and into the professional sphere art/design is not subjective. We are at the stage where we are accepting anything from AI art (ever watch a movie from the 80s and make fun of how low-tech and special effects are? We are enamored by AI, anything goes at this stage. It will not last).
Part of the reason for the subjective misunderstanding of art is that arts education has been destroyed (at least in the US). So this common misconception comes down to ignorance (that is not an insult, ignorance is defines as simply not knowing something). People mistake their artistic taste (what you personally like) with good art. But that is a bit arrogant because it's not about us personally. Art has a long history that has followed humans through our entire timeline on this planet. There is a lot to know about this topic including history, materials/tech., the conventions, as well as specific (and logical) things about our (humans) eyes and brains etc. So just because someone likes it does not automatically make it good art (or even art for that matter). You have every right to express your opinion and like and dislike whatever the heck you want, and I will agree there a some grey areas when it comes to art, but most professional art is uncontested by people who know a thing or two about it. The more a person learns about this (and any subject), the more we understand the subject.
My prediction is that the court cases will get sorted and AI art will be in the same category as any other technology artists’ use (rulers, the camera, digital programs, etc.). AI can spit out these hybridizations of stolen images and we may eventually call this art someday, but we are not there yet. It's going to take artists to train it to ultimately make great art. Hobby artists will feel good about using it, just like we do with the cameras on our phones. But without understanding the subject and all the nuances of image-making, we will be amateurs and that’s okay! I can enjoy a bike ride, playing basketball, or even guessing where my liver is without become a professional athlete or medical professional. No big deal, it will be what it will be. AI needs humans for input. If AI technologies become artists then it would be sentient and we (humans) have bigger problems than to bicker over the "arrogance of artists".
