Why does vim depend on vi?

Question

Running a very minimal machine in minimal space, I have a custom vim package that strips out gui, perl, python and ruby intergration because i don't use any of those features. i was thinking of also removing vi to save try to save the 28 megabytes (it is important, its a 2 gig usb stick), since vi and vim come from the same source and I initially though they really shouldn't need to depend on each other.
However, it turns out that vi creates the /usr/share/vim folder which both it and vim use and need. This looks like the only reason vim needs vi, and obviously its done this way to prevent package file conflicts. The 28 IS pretty much the size of the /usr/share/vim folder, so its a stupid space "optimization" to persue, as without vi, vim would just be that much bigger itself, but for curiosity's sake, is it possible to build vim without vi? I couldn't figure out what trick causes the vi PKGBUILD to include it and the vim one to drop it. What causes vi package to create a /usr/share/vim and prevents the vim package from doing the same?

Answer 1

Also, vi lacks X support and vim is compilled --with-features=big while vi only has --with-features=normal.
Vi, for example, won't do 256 colors.