Well, there is a difference between "hey, we have this cool service you'd like but we need to process your voice data; maybe or maybe not we're doing something else with it" and "we're forcing ads down your throat and hey, now everyone can MITM you and rob your bank account clean".

"Hey siri" is only enabled when your phone is plugged in, and it processes that particular phrase on device, not across a network.

If remember correctly their devices were sending back GPS coordinates to a server too?

The difference being that only Apple (and the us gov) can listen in, not the entire world.

Huh? How so?

The big difference is that "Hey, Siri" isn't a privacy threat at all, and that Apple doesn't generally allow people to snoop on all of my supposedly-secure traffic and then say "oh, there was no problem" when confronted with it.

About the closest they've come to that was the "goto fail" bug from a year ago or so, and that gave every appearance of being a mistake, and Apple didn't try to claim that it wasn't a problem (although they were, as usual, pretty quiet about the exact nature of the problem).