What would you do, oh brilliant one? Shear them in the winter? Summer?? You obviously know less than nothing about raising sheep!
Sheep are sheared in the spring because that's when their wool is at its finest.
It's also the time of year when the vast majority of lambs are born. I guess them dumb collectivist sheep don't know no better. (sarcasm off)
I'm no shepherd ... but he said "mutton" is available all year long, not wool. He wasn't talking about shearing them, but about slaughtering/butchering them.
In which case - and I freely admit my ignorance about such things - it seems to me to be true that "mutton is available all year".
Is there any reason that a sheep can't stick around for six or eight months after its last shearing?