Besalel
The owners of Artscroll are not of Sefardic descent, I think you can excuse them for focussing on Ashkenazic gedolim.
I would hope that there is also a Sefardic publishing company out there that puts out books on Sefardic Gedolim and if not its the Sefardims fault for not doing so. Go do it! Blaming Artscroll is so lame and pathetic.