The people that dislike them generally argue they are overused. I'de rather use the term iconic.
Nope, they are overused.
Fallout- You can't beat the game easily without running into the BoS
Fallout 2- Avoidable, but they still play a role in the series
Fallout:Tactics- You play as an initiate, the whole bloody game is about the BoS
The Burned Game- BoS play a key role in it.
Fallout 3- Railroads you into helping them
Fallout:New Vegas- No faction can avoid them despite Obsidian saying you wouldn't have to run into them in the game.
They ARE overused. For once it would be nice to find a way to use Power Armor WITHOUT the freaking Brotherhood. In Fallout and Fallout 2 it had repair manuals and instruction books, so we could just find and read one of those. Iconic implies it's a key part of the series. It isn't, it's the cash cow of the series. I'd rather the BoS just die off like the idiots they are.
Edit: GABRIEL HOW COULD YOU FORGET LIEUTENANT IN YOUR LIST?!?!