I care for two lovely sheep, and have cared for others in the past. Sheep DO need to be shorn.
However the industries that you buy wool from do not look after their sheep like 'pets'. The sheep are cared for on a monetary basis. They're often docked and mulesed with no painkillers. I was reading an actual veterinary article on the care of sheep, and EVERYTHING is based on money for the industry. Sick sheep are rarely treated, as this wastes money. Infections are treated by sticking a knife into the site to let it drain.
My mum once made a scarf from the wool of one of our pet sheep. There's nothing wrong with that. The wool isn't anywhere near the quality of shop-bought wool as this was grown on a happy sheep who did get dirty and did rub against things etc.
So it isn't really the shearing of the sheep which is cruel, but the way they are raised, handled, and treated.
Same with the whole, 'a chicken lays eggs anyway'. Yes, it does, but battery hen conditions are cruel.
Hope that makes sense and is helpful to you