I guess the objection is simply because with only the latest example code, it boils down to
class MyClass
{
public:
MyClass() : ptr_(new something) {}
~MyClass() { delete ptr_; }
};
That on its own is usually not just pointless ("something" should just be a regular member), but also a time bomb just waiting for an instance being accidentally copied (assigning it or passing it to a standard container). So usually whenever you see this kind of pattern and it really is necessary, explicitly making it non-copyable or supplying assignment and copy constructor should become almost a reflex.
Since this is just example code, it most likely doesn't apply, but still, I've encountered production code where the author thought that setting the pointer to NULL in the destructor will somehow magically affect all the other objects that have a copy of that pointer.