My bar is more for prying rocks or trees out of the way, but yes, it can be used in the sand. That thing is damn near immobile when you pound it down to the eye in sand. It used to be a 4' utility pole anchor. I cut the spiral steel anchor end off and chisel-tipped it.
That Cabela's thing doesn't look all that strong...and they don't specify a weight rating on the website. I wouldn't really trust that thing to hold the weight of a 4200 lb Pathy stuck in the mud. A quad, sure, but not a Super Duty like they have in the picture.
I've been thinking about making my own land anchor too, should be a fun project.