И вы надеетесь что компилятор сможет создать конструктор копирования для класса содержащего некопируемые объекты?

определить конструктор копирования видимо

No copy constructor or assignment operator
QObject has neither a copy constructor nor an assignment operator. This is by design. Actually, they are declared, but in a private section with the macro Q_DISABLE_COPY(). In fact, all Qt classes derived from QObject (direct or indirect) use this macro to declare their copy constructor and assignment operator to be private. The reasoning is found in the discussion on Identity vs Value on the Qt Object Model page.
The main consequence is that you should use pointers to QObject (or to your QObject subclass) where you might otherwise be tempted to use your QObject subclass as a value. For example, without a copy constructor, you can't use a subclass of QObject as the value to be stored in one of the container classes. You must store pointers.

The values stored in the various containers can be of any assignable data type. To qualify, a type must provide a default constructor, a copy constructor, and an assignment operator. This covers most data types you are likely to want to store in a container, including basic types such as int and double, pointer types, and Qt data types such as QString, QDate, and QTime, but it doesn't cover QObject or any QObject subclass (QWidget, QDialog, QTimer, etc.). If you attempt to instantiate a QList<QWidget>, the compiler will complain that QWidget's copy constructor and assignment operators are disabled. If you want to store these kinds of objects in a container, store them as pointers, for example as QList<QWidget *>.

pastor типа "мы не смогли договориться как сравнивать QObject'ы и потому запретили это делать нафиг"?

Пояснение этого приводится в ассистанте в описание Qt Object Model

А как можно сравнивать QObject, а как можно сравнивать его наследников?
Как можно сравнить QListView и QFtp? Кто больше?