Somali republic was eligible to join the organization since the independence as we were part of the Arab world but the civilian administrations didn't submit their request to join it until the junta came in.So? Maybe you should accustom yourself with Dadka Soomaaliyeed, go to Somalia and ask them "Ma waxaad tahay Deghace?"
I literally lived in Djibouti and the Arabs were clearly distinct and considered different by us Somali.
A political organisation like the arab league was just that, a political move by the young Somali Republic to get allies. That's why 3 years later the chief states in the arab union would show support to Siad Barre when the communist world shunned Somalia.