They have different reasons,
Hawiye hate Somaliland cuz they don’t want be stuck with darod
Darod hate Somaliland cuz isaaq stopped their gravy train in barre’s Gov and now they have been forced back to their under developed regions while before they used to chill in xamar, hargeisa and burco.
Puntlanders hate Somaliland because they wish they were actually part of it, see how many times punrlanders say puntland and Somaliland should join and break away, even the last regional governer of puntland faroole is on record advocating joining Somaliland. Everything they do is literally inspired by Somaliland but they can’t break away because they have a tiny population and not enough economic self sustainability.
Those in Ethiopian k5 region know the chance of them getting freed is nil if Somaliland leave Somalia.
Those in jbooty don’t want competition. They literally went crazy when DP world took over berbera because it meant Ethiopia would have different access to the already expensive and congested jbooty port. You see ciise kids like
@Kingcobra advocating for Somaliland to join Somalia but isn’t advocating for his tiny french oven to join Somalia
So all in all, it’s differeng reasons but the biggest one ‘if I am in a shitty existence, you should also be in a shitty existence”