The bigger hurdle is that security actually works against usability, because you have to build something that works on arbitrary networks with who-knows-what co

The bigger hurdle is that security actually works against usability, because you have to build something that works on arbitrary networks with who-knows-what configured and no guarantee that the consumer has access let alone knowledge of how to fix random networking issues. Granted there is plenty of low-hanging fruit with minimal usability impact, but if we want to talk about actual decent security that is a very difficult proposition for a plug-and-play consumer product regardless of customer demand.