I know this is going to be a flamebait. But before you flame me, consider the following: I'm researcher and get paid for what I do. I've released quite a few codes as open source and invented a bunch of algorithms which are not patented and used in many applications (think email spam filter, face recognition, etc.). And I've worked in industry and academia. For almost two decades. So I know both open and closed source.
First off, ideas have value. As in Dollar value. Take NVIDIA for instance - they don't have a semiconductor fab, so they send their chip layout to a place like TSMC or Global Foundry or Samsung or any other place to have their files turned into chips. These places are like modern printing presses. If their mask, vhdl or layout information were open source they wouldn't be able to reap the benefit from their investment into building the next generation of chips. Or as a more extreme case, take ARM. They design processor cores and license the microarchitecture to other (possibly fabless) design companies such as Apple which, in turn, tweak the design, add more stuff to it, and then ship it to the foundries. In other words, all the good stuff is in the plans, much less in the actual hardware.
So, designing an open source CPU is probably not going to work. Why not? Well, unlike with software, there's a massive barrier to entry. Talk Millions of Dollars rather than a few hundred to buy a laptop and install some version of GCC on it. Few users can afford this. This pretty much kills the model where many users take advantage of a good idea and share it to make it better. Yes, there are good ideological reasons but most people don't do things for ideology (note the emphasis on most). They do them for fun, profit, fame, convenience, or some other less noble goal.
As for the piece of hardware itself, hmmm, not sure why I would want to buy an overpriced and function limited and incompatible device.