I don't see that as an argument for distinguishing between physical and non-physical, but as an argument to, maybe, have an exemption in the law for cases where the cost of making things accessible is large relative to the ¿production cost? (given today's technology, that would exempt about every video, so not a real option, given the goals of this law) ¿total margin on that product? (that would exempt every free product, so not a real option, either)

I can't see a way to define the limits of such an exemption without getting collateral damage, so maybe, this amount of collateral damage is about the best we can get?

Also, in the Berkeley case, part of the reason Berkeley deemed the costs too high was that Berkeley had a large backlog of such videos. They have been making new content accessible since spring 2015 (that content also is behind their firewall to prevent 'pirating' (http://news.berkeley.edu/2017/02/24/faq-on-legacy-public-cou...: "Pirates is a term used to describe websites that embed YouTube content without the permission of the original copyright holder for profit. UC Berkeley legacy Course Capture content has been discovered on for-profit websites, which use either a subscription fee or on-page advertising"; "UC Berkeley stopped posting course lecture videos publicly through webcast.berkeley.edu in 2015 as a way to reduce costs and increase adoption.")