TL;DR - Yes, but maybe not how you are thinking
Here is my $0.02, both as a part of Mycroft and as an individual.
With pervasive voice control systems, privacy is a huge concern. I honestly don't think any of the current players is actually doing anything nefarious, but the possibility of bad things happening is absolutely there. And unlike using a laptop or even cellphone, these systems are being designed with the intention of being able to hear every word you say all the time -- that's what makes them useful.
So more than probably any other technology that has been developed, the ability to verify what the system doing is really important. That is why an Open Source platform makes the most sense. The more open the better.
But I'm a pragmatist. I understand that an actually usable voice control system requires very good Speech to Text (STT) to be anywhere near usable. And if you aren't in that 90+% accuracy rate for the STT, nobody will use it. Mycroft's early experiments in OpenSTT built on Kaldi were more in the 80% accuracy. Which sounds decent, but the reality of that figure is that 1 out of every 5 times you try to use the system it'll be wrong. It won't take long for that system to be abandoned, no matter how dedicated you are to Open Source.
So we need better Open Source STT, right? But you can't just make that materialize. You need lots and lots of voice samples in different noise environments and with different pitches and accents to train on. So we have a classic Catch-22 -- until the OpenSTT is better, nobody will want to use it. But you need people to use it to be able to gather data to make it better.
So in the short term, we are being pragmatic and using what is undeniably a very good STT engine at Google. But we are protecting privacy by breaking the connection between your Google identity and your speech to text commands/queries. We do this by being a proxy -- all they Google system knows is that some Mycroft device is requesting a STT translation, but they don't know which Mycroft device or (most importantly) which user. To me as an individual, that is pretty reasonable privacy.
Then we can begin capturing (with user permission and anonymizing it) the voices and results of the Google STT to gather those mounds of voice data needed to train OpenSTT to make it better. THAT is the turning point in OpenSTT which breaks the Catch-22.
So yes, we are working on OpenSTT although much of it is the indirect effort of creating the environment and mechanisms we need to collect the data so we can build it.