When specifying alignment and justification of text, CSS needs to allow you to specify how justification is to be applied to mixed script text. The top example on the slide shows how one approach can cause inter-character spacing to be applied to ideographic characters but not Latin text.

Properties to control justification will also allow appropriate types of justification for various different scripts, for example ideographic, indic scripts with baseline connectors, South-East Asian scripts that don't use spaces between words, cursive scripts like Arabic, etc.