Playing a bad guy is pretty much the realm of smaller games,
Mass Effect took 3 games to tell the story.
Fable, uh not exactly a great series, small game, and the 3rd amounted to being a platform to sell players stuff for IRL money.
KOTOR...Star Wars it makes since.
Dragon Age Series
The thing that gets me is that for the most part the scale of these hallmark RPG play as good, bad, or neutral games is that.
1) small world scale
2) larger scope of options sure but its all basically non-action
3) small amount of dungeon crawl
4) world has very little amount of interactable objects in its space
5) the path of the player is strictly controlled
-Like it or not large amount of areas in those games are entirely off limits until conditions are met.
6) Much larger development teams, like 5 to 10 times the size
7) If RPG isn't really your thing you wont enjoy anything else
8) relatively long cut scenes that get in the way of action oriented players
-Cant actually stress this enough!! Long Scenes are long and get boring when playing the game again to see the other outcomes for some of us at least...
9) Canned Options sometimes come into direct conflict of how awesome the player is due to optional side content that the player may have completed..
9a) You found the uber sword of god slaying but late game NPC's act inappropriately in accordance to your awesome ability at [censored] slapping people that so much as make an inappropriate comment in your prescene....I really hate this about such games.
9b) You cannot kill people in those games just because you feel like it either, so what about essential NPC's that's been a plague on a lot of games since Ultima
10) Since the focus is almost entirely on the RPG aspect much of the combat really isn't as satisfying as it needs or should be when compared to other games.
-Witcher you really don't have any say in how Protag stabs someone it just happens
->Same with Dragon Age series
-Mass Effect 1 and ME 2 also felt lame in regards to FPS mechanics
Apparently there are options for games out there to satisfy those that need RPG with lots of Options.
Thing is that is not the primary focus of a Beth Game,
The thing that they do well is Dungeon Crawls, World Spaces, Combat (yep it can be said that they have done a decent job with combat now), Mods, and pretty much the ability to just up and go anywhere without being tied down to a quest to go do it. You don't have to quest, and there will be plenty of stuff there that's interesting in the environment and not all the stuff found even ties into main quest nope it might have nothing to do with story or lore but its still in the game providing insight of its local inhabitants that lends an amount of believability to the idea that people are living in the area.
There are a lot of systems at play in a Bethsada game that often get entirely overlooked when comparing games, this is unfortunate but anyhow those systems are for the most part entirely absent in every game people throw at a Bethsada game to "compare"
The only thing that can be believably be said is that Bethsada doesn't have an A+ RPG element but that doesn't detract from its games for me and many others.
There are in fact a lot of people that play Bethsada Games that would be dead set against the steps that would be needed to turn Bethsada Games into clones of your other preferred game.
Like a more fully fleshed out back-story, given how the small amount of back-story has created many lengthy threads on how Bethsada betrayed its fans well its just funny but for the most part those other games have more back-story and/or a means of picking options to flesh out the back-story....This would not go over well at all with a BSG game and its fan base.
More Options in Dialogue means even more problems, see those options all have to be accounted for if they are given...That's a much larger task than people want to think. Doable sure, but it does have an effect on scale. Developers don't want to spend time on something like that when its unlikely to be seen or appreciated, more time spent on something like that the more they want to force you to see that pathing or thing that was made...Only makes since.
For the most part it seems overly clear to me that Todd and crew don't really care for fulfilling evil doer fantasy. Of course it just may be that they didn't see any real reason for why the quest they opted for and its tone would even cope or adjust to such a play through... Perhaps they just didn't want to build that in.
Overall Issue,
Despite the many games in the RPG genre making claims to being "open-world game" what is often overlooked is that those games are very much on Rails still.