- It shorter.
- It is open to be interpreted as "Digital Restrictions Management", a term of importance for the Free Software movement. (see https://defectivebydesign.org/what_is_drm_digital_restrictions_management)
- "Digital Rights Management" is a loaded term, used to transport a specific meaning (Of course, the same is true for "Digital Restrictions Management". Note that I do not propose to use this term as a tag.)
Context: Does the GNU GPL 3 prohibit DRM?