This is like complaining that your modem cannot be upgraded because you can only talk to it via the AT command set, while other types of modems (i.e. winmodems) require that you do far more processing in ram, and therefor require lots of special drivers.
I'm actually very happy with everything that runs on the ARM now being open. This means that as these pieces get accepted the the upstream kernel I can now compile and run my own kernel on the pi, while getting full graphics support and without having to wait for any vendor to update their drivers.
In many ways this is far better than the situation for just about everyone on x86 systems. Yes, you can run the open drivers for AMD and the reverse engineered drivers for NVIDIA, but neither of those options will give you the performance of the closed drivers.
The fact that this is a high-level interface to the GPU does limit some things, but it also makes it possible for the GPU to optimize things that it couldn't do if the lower level interfaces were exposed.
Would I like the source for the GPU firmware? Sure. Especially with the DSI and CSI (display and camera interfaces) requiring that they be accessed through the GPU there are things that the hardware could do that we can't do with it since we don't have this access.
But this is a very good step in the right direction as it now means that everything that runs on the main CPU is open.
note that they are speculating on the option of releasing a different version of the pi hardware that would have this firmware burned into ROM instead of being loaded through the bootloader. This would satisfy the FSF and make the device both more expensive and less flexible. I hope that they do create such an option someday, simply so that we can get proof that all those people who whine about closed firmware won't actually pay more for something complient with their demands.