It'll take more than a few 2+ year old Xbox 360 consoles failing simultaneously with kinect use to indicate the slightest causality here. I'm pretty sure you could find several PS3's which failed right about Move's introduction if you looked into it, so unless the failure rates of (older) Xbox 360 consoles have become noticeably higher, then it's probably a new spin on an old story;
Some - usually older - Xbox 360 units still breaks, and some people happened to play kinect when they did, attributed this new situation to kinect, wrote about their suspicions on the internet without the slightest technical knowledge or statistics to back it up, and we jumped on it and dramatized it without any technical analysis or statistical data at all, relegating their suspicions because large companies screwing consumers over is always a good story.
Of course, if it turns out there is a measurable technical causality, then it should definitely be reported on and Microsoft forced to fix it and offer due compensation. Doesn't seem to be any convincing indications so far though.