The very spirit of Roleplaying, is not putting yourself in an immersive world, but emphasize the role of "In Character", that is a state of "Not You". Simulation on the other hand emphasizes on "Out of Character", that is the state of "Being You". You can have horrible simulation in an RPG, but if you put poor graphics and very unreal surrounding, you get a horrible simulation.
Many argued FPS is RPG, or action game, or any game is RPG. That is where everything got mixed up. Back in the old days RPGs require you to answer questions to establish mannerism, behaviour and personality for your character. You make up things, you build a new person, then play according to that constructed person in the simulated world. There is no you, only your character and NPCs. As technology improves, the simulation part gets better, people began to forget what it really were about roleplaying.
Roleplaying is like drama, acting, performance, it's a change of inner self to response to an imaginery context. Simulation puts oneself into a virtual context, feeling and experiencing what has been given by that preset simulator. I can roleplay and act when there is no substantial context, but you cannot simulate when the latter doesn't exist. So in much simple term, you act "In character" and stay "not you" in an RPG, but you stay "out of character" with "you" being the primary perception while playing FPS. That's why you can be male, female, Reguard, elf, dwarf, and be given choices to define your character, the "not you" part. In FPS, you can choose between characters, but once that's done, you are back to the regular "you". You've been put to the shoes of you in something given a so called "role" and following orders killing things clicking on dialogue boxes, but you never get to define the character you are using. You are souless, you are just a cardboard miniature puppetted by a real life person. Roleplaying asks you to puppet a character with a soul, an idea, a culture reflected by players. So in conclusion if the game itself doesn't provide you the feature to define your character, it fails as an RPG.
Of the 16 years being a GM, I found people in recent 5 years are having more and more difficulty in realizing what "In character" and "Out of character" is. When their character's being killed, they would assume the GMs are picking on them, GMs killed them, GMs did not give them any chance, GMs were unkind to them when an NPC was yelling at them. They failed to realize the GM was merely roleplaying the NPCs, acting like in drama, pulling himself out and showed as an "In character" perception to react to them. Action is part of RPG, a tool to make it more exciting as a game, but stepping to deep in there, you distract its theme to something else, gradually losing the taste that defines RPGs.
So when Bioware developers said the line of RPG has blurred, I'd suggest they go back to tabletop games and recall their good old days of RPG before getting back to put up so call RPG titles. Individualism plays a big part in there too. When a person is deep down thinking from "self" perception, it is not uncommon to have one losing the grip of other's perception on self. Immersion improves your perception beginning from yourself, by providing realistic, reactive environment. Think deep and you should realize you never really lost yourself, you simply were captured by the surroundings. You never lost the "You" in there, you are still a British/American/African/Asian (whatever you are), you are never a Nord nor Colonist. So just remember, RPG changes "self", simulation changes the "outside". When you can't understand what RPG means, or still call Diablo and Borderland RPGs, try to get acquint with people who do drama or get on stage, ask them about "in character" and you shall find the beauty in roleplaying. If you can't get into that part of thing, then most games you play are likely not RPGs, cause you cannot enjoy playing the "not you" part.
