First, %AppData% is a subdirectory of %UserProfile%, so it's not like
this is a totally different place.
More importantly, we are following the platform guidelines, which
say:
CSIDL_PROFILE Version 5.0. The user's profile folder. A typical
FOLDERID_Profile path is C:\Users\username.
Applications should not create files or folders
at this level; they should put their data under
the locations referred to by CSIDL_APPDATA or
CSIDL_LOCAL_APPDATA.
When Emacs on Windows starts up, if %HOME% is not defined in the
environment already, Emacs defines it to refer to %AppData%. See
w32.c:init_environment for more details.
I think we are, as much as practically possible.