This has always been a sore subject for me, other than locking in the pink color and curing it for long periods of time, it seems fairly pointless to me, bacon tastes just the same without the nitrites, in my experience it is perfectly safe within 3-4 weeks (had some grow mold once it sat longer than that)
and nitrites are "perfectly safe" but with the caveat that they are only safe in small amounts, problem being that just about every commercially made processed meat product contains them, and with the sheer amount of additives, preservatives, and etcetera in todays products, its just not healthy