cannot understand "CALL METHOD super->constructor."

In abap oo programming, we know that constructor of each subclass must contain a "CALL METHOD SUPER->CONSTRUCTOR" statement in the implementation. But that's kind of weird. For example:

if the constructor of superclass is to output a constant like "write xxx", but I do not want to do this in the subclass, why I have to call SUPER->CONSTRUCTOR??

I really can't get it.