The way out of Somalia's political impasse is not centralization. Somalia had a centralized government for 22 years before its collapse. Out of those 22 years, only 7 years(1970-1977) did Somalia experience a golden age and relative peace and economic growth. Even during that period, the Somali state encountered many shortcomings and problems. There was corruption, brutal repression against dissidents and mismanagement of Somalia's resources. After the Ogaden war, the country started to slowly disintegrate.
The ICU did the unthinkable and I give them credit. They established peace and stability for the first time in 16 years. They drove out the ruthless warlords from Mogadishu. They slowly began to re-establish the economy and provide vital services to the Somali population. The hardliners amongst the ICU wanted to rule all of Somalia by force similar to Said Barre. Even professor Abdi Samatar advised the courts against their expansionist adventures and blamed them for the massacres of Somalis. The ICU didn't want to decentralize power or hold peace talks with their rivals. They didn't want to negotiate with their rivals in shape or form. This led to their ultimate downfall.
Even Ahmed Madobe, who was then a member of the ICU, criticized their system of governance. When the Islamic Courts invaded Kismayo they encountered huge opposition. What did they do? They brutally suppressed their opponents. May Allah curse me in this life and the next if I am lying. I lived in Xamar during the reign of the ICU. I even witnessed the Ethiopian invasion. Yes, the Ethiopian invasion was part and parcel liable for the collapse of the Islamic Courts Union. But you need to look at the ICU from different angles to have a better political understanding.