This is very helpful for processing which treats each pixel as a sample of the scene, such as computational microscopy or remote sensing. I've always wondered if that had something to do with why it was hosted at remotesensing.org.
Viewers of libtiff often treat it like PNG/JPEG, but good Tiff viewers can leverage this functionality. Typically few batteries are included.
Tiff is kind of a cross breed between structured portable formats (HDF5/NetCDF) and imagery.
1. On-disk size
2. Compression/decompression speed
3. Access speed (for use in image analysis algorithms, editing, compositing, etc)
4. GPU friendliness (which operates in warps on small blocks of contiguous pixels in image space)
TIFF doesn't really optimize for any of these (not even #2 since in-memory decompression can be faster than paging uncompressed data from disk)
It's being slowly replaced by HDF5 for some applications.
But all of the features you mention above are tunable and are in practice perfectly fine with TIFF containers.
Yes, but for most image formats they aren't defined. They are for TIFF.
The problem, of course, is that if you use an exotic TIFF feature, very few TIFF readers will understand you.