This is mainly due to historical reasons. Old compilers (Fortran IV(66) and before) were implemented to produce programs using mainly static memory. Old machines even didn't have any stack. Therefore the programs behave, as the variables were defined as save.
The predecessor of the variable initialization, the DATA statement, is more like defining an initial content of static memory (similar to the directives for the data segment in assembly), than the on call variable initialization you may know from C. The syntax became similar to the C variant later.
