A military action, even a colonial invasion, to "pacify" a place and to take control of it has little to do with a full annexation. The US did not make Afghanistan a State... And even among European colonial empires Algeria is quite unique.

France had lost most of its Empire during the Revolution and Napoleonic period so was keen to rebuild one. France did not have a settled Canada or Australia, either, so perhaps this also played a role but it seems unrealistic to believe that trying that with an Arabic Muslim country could have ever worked.