People say wild hog tastes bad/is unsafe for three reasons. Wild hogs don't stand around, eating corn and soy all day, so they're very, very lean and muscular. They're also tougher, because they aren't slaughtered as pudgy teenagers like commercial hogs. The worms bit comes from "zomfg, trichinosis", which is a danger from just about any animal, including walrus...es. (Wal---ri?) Key line from that document:

Although trichinellosis in the United States has historically been associated with consumption of pork, multiple nonporcine species of wild game also are competent hosts for Trichinella spp. and have been collectively implicated in the majority of trichinellosis cases since the late 1990s.