Only problem I have with it is the lack of quests (there's not enough. not there aren't any) and starting equipment being a bit shit. Yeah, you can't start with a combat shotgun, 200 shells and metal armor, not the best equipment but you see what I mean. But that's part of it. I chose to roleplay myself and make it up as I go along.
My latest character is a slaver and a childkiller. I play the game "as me", meaning when I type something out, it's me saying, it I am not pretending to be anyone, and when I make game choices it's more to benefit my character rather than "what would blah blah do"?
But I made up my own background. My character is my age, so he's a young adult. Using my interactions with other players I decided he'd been abused and lied to often by other wastelanders and snapped one day. He encountered a family working on their farm in a rage after being beaten half to death and having his possessions by everyone he encountered, he thought "Why the fuck should I be the nice guy?". He killed the children and enslaved the family, only to sell to Metzger later on. Later, he found out about the raiders after running jobs for Metzger and joined up with them, killing and enslaving anyone he can.
You start off with a blank slate. Make it up as you go along. The best kind of roleplay is one you make yourself.
It'd be shit if you had to choose from "Vault dweller/tribal/settler" backgrounds and choose different paths in a slow as fuck, drawn out intro part of the game like every other MMO out there.
You start with nothing and are no one. Then you can make it up how you want, when you want.
Fuck it, my first character was a miner, someone who worked the NCR mines and sold the ore and minerals in bulk to other players and I FUCKING LOVED IT.
Just do it yourself. Gamers who demand everything on a plate aren't gamers at all.