>>720332130 (OP)
The way the "roleplaying" works in this game is the way they expect real life to bend over backwards for them. The game removes anything that could possibly conflict with whatever bullshit narrative the player decides on in their head beforehand. You have no backstory and are never forced to do anything you don't want. Nothing even challenges you.
Look at Fallout 3. You cannot join the Enclave because they want you dead. If it was NV you would be able to join them at any time by cheesing the system to get the required number of whatever points it would require. And once you do join, it would be devoid of any substance. All "quests" will be completely sanitised cookie cutter bullshit that you can just skip by reading a magazine and talking to someone.
In Fallout 3, you can try not to kill people but how far you can get before you're forced to do so depends on random encounters and where you end up(since 3 is actually open world instead of on rails). In NV you can just go through the whole thing without killing anyone, no matter the circumstances. You just have to cheese the system, or pretend the enemies don't exist and just run away.