Steam Family Share Loophole

I was hesitant to report this because i knew some ppl that used it to test out the game for couple of hours but this would maybe help with cheaters.
Why is the game sharable? Steam family share is enabled. The amount of new accounts and cheating alt accounts that could be created is abysmal.

https://www.youtube.com/watch?v=9LQ84YLZ8wc
This video proves that if there is an actual loophole, more situations like these could arise across different regions.