Why not pasture raise hogs?

I have about 10 acres of pasture i havent done anything with yet. My original plan was to raise a dozen or so cows on it, but the start up cost is high, soninwas thinking about hogs. Is there a reason you rarely see anyone pasturing pigs? I know they root and dig, but at the same time it takes 4-6 months to raise them from feeders to butcher, which leaves adequate time to rework and reseed the ground. My only pork experience has been raising them in a shed, which at the current market price and feed price is a losing battle. That being said, according to the research ive done you can run round about 10 hogs oer acre of pasture with minimal extra feed, so even with the current low pork prices it seems like it could be profitable. So my question is, is there a viable reason NOT to try it?

Why not pasture raise hogs?