First I just want to reiterate it is just speculation on my part.
But as for why you can use the workaround, I would guess they're just following specifications to be compliant with any DRM specifications. If this is the reason, content providers have been doing this for years. I remember when MSN Music was shutting down and they said after a certain date you would no longer be able to transfer your songs to a new computer, and their "solution" was to burn the songs to a CD and them rip them to the new computer. This was always possible but to get the deals with the record labels they sure as heII weren't going to advertise it. Same concept when iTunes only allowed you to burn seven CDs from the same playlist - you could get around it by changing just one song in the playlist. You could argue MacroVision was the same way - you could defeat it fairly easily if you wanted to. And the fear of providers implementing audio DRM is what sparked the initial backlash to the removal of the analog headphone jack in iPhone 7s last year. Goes back to the notion that all DRM does is hurt legitimate users.
Again, I am not a very tech savvy person but it wouldn't surprise me if this was the reason. Reasonable assurances of anti-piracy protections to the providers.
