Except Siri is disabled by default, so.... Personal accountability plays a role here. Don't enable a feature until you understand it's options as well as risks.
Maybe my experience was different than yours but I was presented with the option to turn Siri on during configuration/activation - doesnt really matter either way. Anyways, The way the default is set now, too much responsibility is put on the user. Like someone said earlier, convenience and security are often opposites but that doesn't mean the user shouldn't get some guidance.
I guess I should start by saying I don't think this is a big deal - Apple could easily change/solve this issue. But to me, the user should get a popup that says Siri is available in the lockscreen without a passcode and how/where to change this - they already give us a popup to tell us to hold down the home key to activate Siri do why not. It seems weird that they went to the trouble of an entire menu, in the name of security, to toggle the amount of location services (because of locationgate) that are logged and yet they largely defeat the purpose of a pass code.
I think if you look at it objectively and weigh all the options, this is a valid question to ask. We all agre that it's a question that shouldn't be sensationalized the way it is being written about by so many sites, but we shouldn't be dismissive of this either.
In the end, i can agree to disagree.