As I said, entry level for efficient GPU mining is much higher than for CPU. It's possible to rent a couple of servers for CPU mining at affordable price or simply use available computers. No need to buy it all. Initial cost of GPU farm is pretty large (and yes, it includes CPU as well) and it must be placed somewhere. I wouldn't count power as important parameter as some regions have pretty low prices.
Yeah, at that level ok. These are larger scale operations that not many people are involved in. For the individual with his one or two PCs its a different matter altogether.
Also, as discussed previously, we are interested in mining power to be more distributed while with GPUs it gets more concentrated. I believe this would lead to price instability which, in its turn, suppresses effective use of the coin. Anyone, except speculators, wants this? The more stable the price, the more rapid adoption of the coin would be.
That is why I believe that it is essential to keep it CPU only and prevent GPU mining as much as possible.
I am not certain of the GPU-concentration dynamic, except through aggregated individual power in multipools. GPU farms are difficult to build and manage, so GPU power is mostly decentralized to simple users who mine with a couple of cards. I believe GPU concentration will never reach the same level as CPU concentration (data centers, etc).
But even so the whole issue of the developers deciding cpu or gpu is kind of irrelevant as it's not really their choice. It's more about the choice of certain programmers who will or won't make a gpu-implementation and whether they will share this or not.
A coin creator can, at most, make the life difficult for a gpu chip, asic-designer or quantum-computer designer by selecting (during the coin creation) hashes which are hard to speed up in the aforementioned hardware. But now we are past the coin creation stage, so...
