[mabbo]

Lots of possible reasons.

Türkiye may have an environment that is very suitable for the preservation of fossil, and one where said fossils remain near the surface. Africa is huge, but may lack areas that both has those hominids and preserved their fossils well.

Fire example, there are very few footprints on sidewalks, but lots in the mud beside them - should we conclude people must prefer to walk in the mud?

[andrewflnr]

Except that eventually we do get hominin fossils there later. And I for one haven't heard of a lack of other fossils from the same time period.