It may be your accent or possibly how you make requests to Siri. I use it all the time. I have learned that Siri wants questions/requests phrased a certain way. I have gotten her to set appointments for me often, as well as search for answers to questions. I have also used her to send text messages to specified individuals. If the request is not phrased the right way, then she can't do it. Its a computer not an android from TV.
In other words, it's not even a useful or usable computer.... which is very true