Free as in embrace, extend and extinguish

Why do the current kernel developers forbid use of the DMA-BUF API to non-GPL drivers, most notably NVIDIA's? Isn't this a violation of my freedom to have better drivers? Why does EXPORT_SYMBOL_GPL exist in the first place anyway? If a module is statically linked to the kernel at run-time, the GPL shouldn't apply as it is dynamic. Why doesn't Linux have a stable module interface? Oh, right.

>>1
Why do the current kernel developers forbid use of the DMA-BUF API to non-GPL drivers, most notably NVIDIA's?
Because they want to force license compliance for all drivers, futile though it might be.
Isn't this a violation of my freedom to have better drivers?
No
Why does EXPORT_SYMBOL_GPL exist in the first place anyway? If a module is statically linked to the kernel at run-time, the GPL shouldn't apply as it is dynamic.
That's not how it works. Modules are considered derivative works and must therefore be GPL compatible
Why doesn't Linux have a stable module interface?
Why do you want a stable module interface? That brings absolutely no benefits what-so-ever. Linux isn't a microkernel in case you haven't noticed.