A lot of steering wheels were just glorified joysticks, few had analog control. So the controls map nicely to modern controllers (even the ones that do have analog control). But fair enough. I guess anything other than 4/6/8/12 buttons was not considered, which explains it.
After Burner is also missing. There needs to be a sort of supplementary list.. it should be a crime to not consider these greats just because on paper they're not using a "joystick + button" combo. Still highly playable in MAME, unlike stuff like lightguns and trackballs which are difficult to play with a joypad.