I can answer with regards to history and presence, not recent internal politics:
...because that ignorance lets them self-define and maintain their delusions about their placement in the region.
Most Kenyans don't know that Somalis have lived in northern Kenya for close to 2 millennia and view "Somali" as a national concept, so they juxtapose Somali and Kenyan as two nationalities because they don't understand that a country like Somalia is a nation state, not an ethno-pluralist society, i.e., Somali being an ethnonym.
Most Ethiopians fabricate our history to expand their false version of the story to create an Ethiopian history paradigm; the Somali factor is an issue and breaks the image of extant engineered Ethiopian spatial historiography defined by imperialistic revisions that try to self-justify.
Much more than you think is going on. Ignorance in these cases is often not a lack of action but a willful position.
The reason Kenyans view Somalis as the other can be found rooted in the colonial legacy that the Kenyan state has appropriated during the post-colonial period.
If they engaged with Somalis as we wanted them to, that would break with their interests. It serves their interests that they engage in propaganda and a bunch of ignorance to expand upon regional influence, at the cost of Somali precedence.
That is the historio-spatial aspect in relation to the average person up to the educated class.
When it comes to the national operations, both Kenya and Ethiopia are aggressively trying to hold power within Somaliland and Somalia. Kenya is trying to vie for power and influence through military control in southern Somalia. Ethiopia wants to circumvent the logistical trade potential of Somaliland while sandwiching them, Eritrea, and Djibouti, by building a naval infrastructure giving sea access.
So, how little do they know if they set out to manipulate the bureaucratic systems and want to expand their influence and effective power by moving critical infrastructure toward Somali lands? Key statesmen in Kenya and Ethiopia are extremely obsessed with the Somali peninsula and know about the inner workings and exploit the corruption more than you.
Don't ever for one second think they are not thinking about us.