This is not a pen and paper RPG. It is a computer RPG. The source material is adapted to the medium. Changes happen.
Correct
In PnP the GM can adapt the game depending on the situation.
He can create challenges depending on what characters you have and how the players play.
In a computer game everything has to be programmed before the player starts playing.
The player cannot know what awaits him.
When I say the game must be a bit balanced I do NOT mean that each char needs to be good in every situation.
But when you add a class into the game, this class should at least be able to get through the game without feeling completely useless.
Its bad when the game presents a challenge that only one specific type of char can do well but the player cannot know this before.
I see no problem here as they said there will be several ways to solve each situations.
extrem example:
Enemies with longbows stand on a mountain and shoot at everything in a wide area below.
The game expects you to disable them with a long range spell or you sneak up and shove them down the cliff.
Oh, you created a char that cannot cast AoE spells or is extremely good in sneaking? You are an idiot who deserves to die.
Everybody knows that it doesn´t work to fight archers when you are good in using swords.
You keep on mentioning the nosferatu. Its true that they added a monster class to a social game.
But they also gave them the invisibility spell and you could reach most places through the sewers.
So you have a class with a big handycap, but the game is balanced in a way that this class has also the means to deal with this handycap.
Prof. Dr. Dr. Mad S. Tist 
