> Before -F, many of the tools would not permit the use of a regular
> file as a file system image; they specifically checked if the
> provided device was a block or character special file.

That sure sounds broken to me, but it also seems to me that the correct
fix is to fix them, not to break them further.

> I wanted a consistent way of allow these tools to manipulate file
> system images without compromising the existing behaviour that each
> tool had with respect to them making specific checks, and without
> requiring interactive user intervention when manipulating fs images
> in files.

This sounds to me like "I wanted to fix the bug while still remaining
bug-compatible".  I don't understand why you'd want to do that rather
than just fixing the real problem (by ripping out the pointless checks,
which are presumably designed to prevent you from doing stupid things
but as you found are actually preventing you from doing clever things).

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