Because that was actually a rare thing to do. Philips often translated CD-i games in localized languages, but not often was the title's name also translated. A clear example is the French version of Thunder in Paradise, which was called Caraibes Offshore. Other than that, game localisations often kept their original name. In the case of Earth Command, most versions were called Earth Command, but the Spanish version somehow got the name 'Comando Tierra'.
[Source: CD-i Community]