Signals are not inherited in the subtype namespace

[gbatori1]

Example from PhoneX:
In Subscriber class there are many Signals are defined. For example, CallAccepted signal cannot be used as the member of the Caller class (with the Caller namespace) so the following line results in validation error:
send new Caller::CallAccepted() to caller;

The User is forced to write:
send new Subscriber::CallAccepted() to caller;

[ujhelyiz]

Our solution was based on similar ideas as static method calls: in Java you can call a static method from a base class, but a warning is reported as it is not recommended. I guess, the Signals are similar in this aspect: even if you are calling them from the descendant class, you want to use exactly the same as base version, and this way there is no surprise where you should look for the original definition.

May I ask the rationale behind this requirement? Maybe I am missing something here...