I hilariously discovered this last night as well (playing with IMA), and removing the creation of that attr would be a huge step back.
Restricting the execution of files one downloads or disabling macros on word documents you download and open would be a huge security win.
These attributes are destroyed by merely coping the file, and are on the filesystem, not the file. It's not like sending a file via email leaks where I downloaded it from.
For most users, this attribute, if we start actually using it, would massively protect, not hurt their security.