You've got to love how these people have obviously never fired a real bow and don't realise it is already in first person. So.. why not have iron sights for crossbows it makes tons of sense.. of wait I forgot;
We're all al Capone
"Everyone fire your tommy guns in such a fashion you miss every bullet!"
"Great Idea boss! Everyone! FROM THE HIP!!"
Why do they need to implement something different now? Answer: they don't.
That seems to be the post of one that doesn't want to challange a dev to make a better game.