Ho! A learning opportunity. I know you're a vegetarian, but maybe this might interest you...or someone.
The chuck sub-primal cut is the shoulder of the cow. As you can imagine, the shoulder gets a lot of use while the cow is alive, so there is a lot of connective tissue which makes the cut tough (fwiw the muscles that are rarely used are the most tender to eat) However, a cow being a cow and not a horse, there is a good amount of fat interspersed within the cut. So while the cut is hard to eat like a typical steak, it has a wonderful meat to fat ratio which gives it good flavor if cooked properly (think stews and roasts). That ideal fat to meat ratio, combine with the grind making it more palatable, the ease of (mass) producing, and low price point for the cut, make it the cut of choice by distributors.
A properly cooked seven bone chuck steak is a taste to behold, though. Far and away my favorite cut, with all of the marbling, on the grill. Obviously, not for you if you like your steak more than medium rare, though, since cooking it all the way through tends to make it tougher than hell.
