Well, if counted as code under your control (so not hardware, microcode, firmware, closed drivers), there definitely are 100% open source solutions, even in the mobile space (Firefox OS). They might not be mainstream (yet ? ;-) ) but they are there. And of course in the desktop and server space, 100% open source is basically becoming the norm, at least as far as Linux distributions go.

BTW, I don't really think anyone is blaming Jolla for closed components outside of their control (hardware, drivers, android emulation, third party code), but people understandably don't like that there are many closed system components that are under Jollas...

I think this is hurting Jolla in the long term, as there are tons of feature requests for many of those closed components. As past performance indicates, the limited development resources Jolla has can't possible handle a significant part of these feature requests any time soon and the community is blocked from helping by the components being closed source.

Of course you can never be sure beforehand if you will actually get any contributions when you open source something, but you can be sure you won't get any if you keep it closed.