What do you suggest they do?
The only thing I can think of is that when they hear the cues that someone needs the emergency services is that they activate but then who is going to be on the other end? You would need it to first send a location then connect and share audio with a person who could determine if help was needed or if it's a mistake. That's a lot of people and you couldn't just use the 999 people because there aren't enough as it is and they need to be dealing with confirmed emergencies. There's also the privacy aspect, where do you draw the line, do you really think the government won't see this as an opportunity to spy on people? Mention drugs, anything terrorist related, something against the government and it gets grabbed.
It's shouldn't happen in my opinion regardless of the perceived benefits.