Nonsense. If Twitch didn’t want people to access that data, they wouldn’t make it available to viewers on the web site. I don’t need broadcaster authentication to go to the page in a browser and get the info.
Which means, ultimately, that I can get the information by using undocumented API calls or by scraping the web site, but I can’t use the official API unless I get the consent of the broadcaster. What exactly are you advocating here?