Siri is more of an experiment than a real feature, it's the interpretation of the sentance that is the exciting part of siri and it's ability to follow a thread.
Whilst there may be some truth in what you say here.
Let's be honest, can you imagine is Siri was not on Apple but on Windows devices, it would be slagged of here as totally useless.
It's only being given the slack it is being given as it's by Apple.