I remember zone blocking starting in high school way back when..In college, it was expanded upon- terminology, etc. Sure, I'd imagine its even more so in NFL, but every OL uses/knows it. Just an initial block (could be a double team with another OLman) with a DE or DT and then a slide upfield to the nearest LB is a simple zone. I just think the media blows it out of proportion, maybe by those who never put a helmet on... don't know.
I think DeCastro gets a bad rap for that injury, imo..chyt happens in games.