The Medium is the Message

"In their time, people railed against these pioneering Pop artists for their then-radical use of appropriated imagery, but today those detractions have largely been put to rest (oftentimes in court), and we won’t waste any more time here defending them." 
-I thought this was a clear and proven statement, and it only solidifies the idea (for me) that all artists are pioneers, and because of that, it is difficult to find fresh concepts. I feel as though at this point, Shepard Fairey is pioneering the art world through his use of political paintings, a series of similar images/faces, and the use of rich saturated tones creates a strong line between Fairey and his colleagues. 
-Why then, do people to this day question pioneering Pop artists for appropriating images?


"The images that Vallen uses to support this claim are almost all examples of Shepard’s street art from the formative stages of his career (1990s and early 2000s), and were sold only in editions of 100 or 200 at $20 or $25 a pop at the time."
- I am confused as to why Vallen is attacking Shepard, let alone a fellow artist. Why is Vallen confronting Fairey, and using early examples (Fairey's work) to try and attack his legitimacy, when he made close to zero profit from the sales? I was also perplexed as to why Vallen would insult Fairey based on his work from previous years, when Fairey had very little credit.
"If Vallen had bothered to open “Supply and Demand,” Shepard’s career retrospective book released more than a year and a half before Vallen published his article on his site, he would have seen many of Fairey’s images reproduced side-by-side with the originals that were appropriated or referenced."
-For me, Fairey's work does not feel appropriated. His reworking of the line quality, color, hue, and composition all rework the original image into a Shepard Fairey piece. Its a brilliant idea for Fairey to place original images next to his reworked pieces; that way, he allows the viewer to decide/critique his work of art
-Why are their as many followers as described backing up Vallen, when clearly his facts, critiques, and accusations have little to none legitimacy?