Here's the thing- BW companions are "special" because of what they add to the game's story. Having a bunch of companions that represent a single worldview, especially if it's completely in line with the MC's worldview, would be redundant, and probably diminish the game's replay value. Instead of ensuring that the companions are so utterly generic that any player can be comfortable with their presence, the writers are more intent on creating distinctive characters with their own established opinions, based on their own experiences. For everyone who wants to murder-knife Vivienne already for some hypothetical disagreement that your hypothetical Inquisitor is going to have with her, other people are excited to get a new perspective on magic in Thedas.
Plus, I have to wonder why anyone would play a story driven game if they can't stand the thought of encountering dissent. How utterly boring would it be if every single choice you could make was accepted immediately, and every word you spoke was greeted with rapture and an utter lack of dissent?