Because they're about to exhaust the existing range
of names for patches?
Because it allows an exciting new category of virus
which is contained in the /file name/?
Because it means that all existing third-party software
becomes uncompliant with the new Windows standard and
has to be re-issued?
Or maybe specifically that Samba file servers do?
(Unless Samba already allows longer paths - I don't know.)
More seriously - maybe they have invented something new
that is going to require longer paths (the way that they've
done it). And it could be about being more compatible
with Linux - not less.