Many people from those clans did stand up, please do look up about people like aun, Garaad Abdiqani who spoke up against Siyad Barre, Ali Khaliif Galeydh a senior Minister opposing the regime and becoming the most senior political exile, Dr.Mohamed Aden Sheick Health Minister and Parliamentarian convicted for treason and spending years in prison, and who then build the Hargeisa Children’s Hospital that has been named after him. Aden Abdullahi Gabyow former Defence Minister who was jailed and later on led the SPM. And many many others who were Senior Politicians, Military leaders, Artist, Academics, etc opposed him from wll Somali clans.
But you need to keep in mind that Somalia was under a military dictatorship in which power was concentrated in the hands of one man, and you will find in each clan people that cheered for him and supported him, and those that opposed him. Somali’s are not bad people, neither are there bad clans but try to look for more facts, listen to different people and what they have witnessed, only then you get a full picture of what happened.