class A {
    void foo(this T)() {
    }
    
    static void bar(this T)() {
    }
    
    template baz(this T) {
        static void baz() {
        }
    }
}

class B : A {
}

void main()
{   
    B b; 
    b.foo(); // ok
  	
    B.bar(); //fail
    b.bar(); // fail
    
    b.baz(); // ok
    B.baz(); // fail
}

onlineapp.d(22): Error: template onlineapp.A.bar cannot deduce function from argument types !()(), candidates are:
onlineapp.d(5):        bar(this T)()
onlineapp.d(23): Error: template onlineapp.A.bar cannot deduce function from argument types !()(), candidates are:
onlineapp.d(5):        bar(this T)()
onlineapp.d(26): Error: template onlineapp.A.baz cannot deduce function from argument types !()(), candidates are:
onlineapp.d(8):        baz(this T)()

run.dlang.io: https://run.dlang.io/is/Hme9vp

Accessing the static type of a class in the context of a base class is an extremely useful feature, and there is no reason to restrict it to just non-static functions, precluding valid use cases like factory function generation etc.