Not sure where you got the impression that the Pi (or anything else for that matter) is 'open source HARDWARE' ..
For sure it's not .. it does however run Open Source Software on a SOC that includes a GPU with micro-code which is a closed source 'blob' (it has to be for two very good reasons -
(1) you can perform H264, MPEG and VC1 video decode on the GPU (and that means a Licence Fee is REQUIRED to stay legal) and
(2) the GPU silicon is an ancient design with a number of 'undocumented features' (so anyone changing the micro-code for one function risks 'breaking' it's operation in other, apparently unrelated, functions)
Whilst I would agree that not having access to the GPU microcode is a bit of a drawback, especially for anyone wanting to achieve any sort of real performance out of the Pi, it was never really aimed at anything other than School kids (apparently the 'hobbiest' came as a bit of an afterthought ..)
On the other hand, where else can you get so much 'free' software (and so much 'free' support) on a system for less than $30 ?