It's more competition for your phone than your netbook.
Of course, it arguably suffers there: 600€ will buy you a lot of phone right now (def more processor). So there's there's a reasonable question regarding whether the keyboard + controls and more open nature add enough value. The answer is probably "no" unless handheld gaming and tinkering is your thing.
It's definitely a more boutique device.
My guess would be it's for the crowd looking for repair ability and control over the device.
Edit: apparently it was presented in 2014... when, yes, dual core ARM would have already been pretty sub-par.
And it seems to be even worse for the Pyra, especially since gpd has finally understood the need and is now manufacturing similar devices.
I think the concept is good but maybe it would be better to design a solid handheld with a slot in option for a pi or some similar form factor sbc. That way, users could actually upgrade the device and keep it current. The hard part these days seems not be the actual computing, but the quality and usability of the screen, keyboard and game controls.