Because the Horn of Africa is generally crap desert or mountainous. Most Somalis are nomadic which is why it's hard to unite them, and they are nomadic because the land is semi-arid unable to support any other lifestyle. China/India on the other hand are perhaps the most fertile regions in the world able to support billions. If Somalia received 1000mm rainfall in all regions, we would have been united 2000 years ago lol. People tend to downplay the role that climate plays on civilization.At-least they were Indian emperors who ruled most of the subcontinent. Look at Ashoka, Chandragupta Maurya and the Mughal Emperors such as Babur, Aurangzeb and Akbar.
Now has there ever been a Somali who has been close to unifying every single somali territory? let alone the rest of the Horn of africa?
Nope. We know little of pre-islamic history so we cannot say much of this period. From what we do know, they were several independent city states, no unified empire/kingdom what so ever.
The closest however was a fascist foreigner.
There was also a British individual whose name I cannot recall at this moment of time who advocated for all of the british somali territories minus French somaliland (remember Italian somaliland collapsed in 1941 and the Britis ruled the former italian colony up until the creation of the UN trusteeship in the late 1940's) to be administrated as one colony but that failed in particular when the ogaden was handed over to Abyssinia following WW2.
For now, let's worry about cleaning up the south from the plethora of issues it has. Once our southern agricultural regions and the capital have been cleansed of vermins, we can move upwards. Let's sort out the territory known as the former Somali democratic republic and move to cause ,fund rebels and stir up anti xabashi sentiments in Ethiopia. The canfar, oromo, sidama, harari, inhabitants of gambela are sick of the xabashi, we should be wise to take advantage of such sentiments.
Regarding the uncle toms of kenya, the worst somali dhabadhilifs/ ? It's a desert shithole for the most part. Tana river is useful and the bantu inhabitants are docile thus we could annex and further expand quite easily. That is if the dhabadhilifs do not betray us. Somali Kenyans did collaborate the government against the shifta warriors afterall. Filthy vermins make me sick.