Public opinion on Satanism has long been clouded by people's misconceptions, as such is the case is here. As far as being hypocritical, I would say it isn't, gR. LaVey never said "Satan is just a symbol" as in "Only believe in Satan in this way". In fact, he took it a step further and dedicated a chapter in the Satanic Bible to the natural variation in beliefs in the existence of "God" and "Satan" among Satanists.
I guess I follow the stereotype of the Satanist, though, being an atheist by definition, only believing in myself as a god, and seeing Satan simply as a symbol for man's carnal, human nature.