Maybe some of the mercenary type of adventures "some" PCs get into is S&S, but the entirety of the D&D alignment system flies in the face of S&S and it morally complex/ambiguous heroes. There is nothing S&S about paladins and priests of Pelor or about BBEGs who are dedicated to evil, not as a side effect of their quest for power, but evil as a real tangible force that D&D core assumes. Any system where there is something called "vile" damage is not a real S&S system.
D&D played as written is a flakey, unsatisfying combination of S&S and High Fantasy Tropes that make no sense when combined. Its not D&Ds fault, because D&D is just a rule set. Every good setting makes the necessary changes in atmophere and mechanics to support the type of game the setting is designed for, be that S&S or High Fantasy.
D&D core is an attempt as playing at Conan's mercenary sensibilities with the cliche of good guys in white hats and bad guys in black hats. How is this accomplished? By making it ok to slaughter evil aligned creatures en masse and take their stuff for your own edification. Its ok because the simplistic alignment mechanic allows one to avoid any real moral choice due to real and vivid evil energy that literally emanates from the auras of creatures of "evil" alignment.
Though useful, the simplistic moral barometer neutralizes the grittiness of the S&S dynamic by making the greedy, self-serving, mercenary killers into "good" guys because they killed the evil critter who live in the hole. In real S&S, no one serves evil, there is no tangible evil force, like the alignment energies found in D&D that allow for alignment based damage and vulnerabilities. This is not to say that S&S doesn't have malevolent or evil beings, in fact the genre has them by the multitude. However in S&S, the villians motivation is not to be a servant of darkness for evil's sake, but instead for power, vengeance, wealth, etc. Also in S&S, evil doesn't think of itself as evil. In D&Dish high fantasy you can have villians serving evil for evil's sake, even going so far as to call themselves evil.
In S&S the villian is often hunted and killed by the heroes who don't usually think of themselves as good guys or serving goodness, they may do it for vengeance, for honor, for their gods, for money, for recognition, etc. The good guys in S&S wouldn't define themselves as "good" guys or "bad" guys but instead just as people with more mortal and often psychologically complex motivations than the heroes of High Fantasy fiction who IMO seem loftier, less human and flawed, and less 3 dimensional than their S&S counterparts.
S&S just seems more honest a definition of the play style of D&D by many groups though the high fantasy concepts ie. the easily pigeonholed alignment system, the mass quantities of magic, the prevalence of spellcasters, the prevelance of magical monsters, the ability to cheat death repeatedly via magic, etc. make D&D core a pureed mess of undefinable concepts that have to be taken apart by the DM or setting designer and worked into something more internally consistant unless one wants to play vanilla core D&D in which case one doesn't mind the uncomfotable marriage of S&S and High Fantasy that D&D represents.
D&D as written doesn't do justice to either genre though a good DM can make the game do either genre justice by working with the atmosphere, mechanics and setting.
Sundragon
