Some tech investors sure seem to be getting defensive lately

Yeah, that's the stuff that happens when you make dodgy decisions based on how much of a maverick you think you are - and then look to invest in other 'seeming mavericks' like you.

Theranos is only the first, as more and more VC-backed companies come close to the border where private funding and public funding meet (commonly known as 'get ready for an IPO'), you will see a steep and shocking correction in valuations. Not a 'bubble bursting', but more of a 'okay, put the bong down, we gotta drive home now' sorta thing.