that is true, but there is a question of whether every academically
interesting or useful to kernel programmers should be included in the
stable production kernel source.
if linux is to be truly successful, there has to be some consideration of
what actual users are interested in.
and as interesting and useful as the ext fs may be from a programming
perspective, the general public does not, in short, care.
no one is suggesting that the ext fs should be thrown away permanently
or any such nonsense. in fact, there is no reason why all the old kernel
segments shouldn't still be available somewhere. but the source distribution
doesn't need to include them all.
matt