Does the new Fuji XF 18-55mm lens make the 18mm f/2 obsolete?

I am looking at the MTF charts of the Fuji XF 18-55 and the 18mm f/2 lenses:

http://www.fujifilm.com/products/digital_cameras/x/fujinon_lens_xf18_55mmf28_4_r_lm_ois/specifications/

http://www.fujifilm.com/products/digital_cameras/x/fujinon_lens_xf18mmf2_r/specifications/

If I read the graphs correctly, the 18-55 lens has better performance at 18mm than the 18mm f/2 lens. Except the half stop difference (f/2.8 vs. f/2) why would one buy the 18mm f/2 lens? I think the 18-55 is a better choice - it's a zoom with OIS and is cheaper when you buy it as a kit with the X-E1

Am I missing something?