I too dislike unfeasibly large helpings - but most of the cost is in wages & overheads, which don't change with bigger portions, so presumably it makes business sense to pander to the heaviest eaters. You don't get this in a posh restaurant of course, as the waiter/waitress will serve you as much or as little as you want.

Incidentally, once upon a time waste food was recycled as pig feed - is this still the case, or was it scuppered by the possibility of Mad Pig Disease?