Because that doesn't work. 2h before someone complains to IT that he cannot write/read/delete said Word document. Then management says X indeed needs access. Now you have created a maintenance nightmare sourced in rather weird security requirements.

Could as well gouge out the eyes of everyone not having a read permission on said document. There are 1001 solution to solve such problems. And as a gigantic bonus it doesn't have to be bound to hardware! User permission management is much easier.