I wonder why there is no 16 bits capture possible in Canons or Nikons?
Let's turn around the question: what information should be stored in 16 bits?
Increasing the bit depth does not contribute to the increase of useful image data on its own.
It seems to be the main advantage in MF backs
MFDBs have higher dynamic range, which requires more gradations. So, it is logical, that their raw images have greater bit depth.
On the other hand, 16 bits are exaggerated. The MFDB owners should think,. that tehy received something valuable for that money, even though they don't utilize it.
Why is there only 14 bits, which don't make a big difference to 12 bits?
This is funny: you are asking, why not 16 bits instead of 14, while claiming, that 14 bits don't make much difference compared to 12 bits.
For your math: 14 bits are *four* times more (in terms of stored data) than 12 bits - just like 16 bits can hold four times more data than 14 bits.
Btw, the Nikon D300 and D3 allow recording 14 OR 12 bit raw data, and as far as I can see, most users stick to 12 bits, even though that numerical range is nor fully utilized.
I am happy with the Canon 40D's 14 bits; that is somewhat more than necessary, but you know, why there is no row 13 on airplanes, no floow nr 13 in many houses, etc?