In my opinion the actual multiplier is a good thing because there a discintion between format and resolution.
Resolution are universal.
Format are very often linked to group conventions, that may overlap or sometimes kills the smallest (HD-DVD vs BluRay)
1440 x 1080 → Rhea 2880 x 2160 (=4k 4:3) → This is not 4K, this is 2880x2160
1920 x 1080 → Rhea 3840 x 2160 (=4k 16:9) → This is not 4K, this is UHD
4K is 4096x2160p and is Theatrical and JVC + Sony videoprojector exclusive
See it here 
