The Clearances caused the destruction of the clan system, accompanied by ethnic cleansing, because sheep were more valuable than people. It is estimated that during the entire period of the Clearances, some 150,000 Highlanders and Islanders were cleared from their ancestral lands. To give a sense of the scale of this relative to the overall population, the total number of people living in 1801 in what are now the council areas of Highland, Western Isles, and Argyll & Bute was 260,000. War, politics, economics and a anachronistic nature of the clan system all exerted pressures that created the monster of the clearances.

A letter to the government of 5 September 1775, represents the most important declaration of the relationship between government and the Highland landlord in the era of first phase clearance.
"the Highlanders were born to be soldiers and the Highlands ought to be considered as a nursery of strength and security to the kingdom"

I think they found out too late that putting a kilt on a sheep did not make a soldier.