These formats aren't complex because they really are supposed to be raw (-:

But yeah, it would be preferable to have them use the digital negative (DNG) format, but why bother when the community makes the work for them? Reminds me of how Bethesda does things.

Traditional Nikon NEF is pretty simple. It's just a tiff. Lossy compression is just gamma-encoding with a LUT (stored in the file). I think most traditional raws are principally similar. More complex compression schemes like ticoraw are fairly recent.

What's complex is the metadata. All the cameras have different AF, WB and exposure systems.