I’ve been arguing against the change as well, and I’m disappointed at the lack of support from Twitch to actually provide easy means to grab content (even as a channel owner).
Many users wish to edit and upload their captured live gameplay to YouTube, and are unable to easily grab this data now. For users like myself whom grab downloads of streams to edit and make store-able highlights are also affected by the sudden change.
While the amount of users whom download raw footage might be only a small footprint of the community, I find it disheartening that Twitch feels the need to limit the exposure of raw files. Twitch shouldn’t cite access control issues when they could limit the API to prevent access where access controls are restricted.