it's not a problem of complete or incomplete romset...Just i see no interest to add over 5000 Fruit Machines Games to MAME (and i'm not the one to think the same thing) even for a documentation and/or preservation project...Now if MAME is the acronym for Multiple Amusement Machine Emulator, no problemo.
Now I am not a hypocrite and that does not stop me from criticizing the choices of some additions though I respect the work of the MAME team !