when making jerky, i don't find it absolutely necessarry to use cure, but i often do use it in place of salt as i like the color and flavor. if i do add tenderquick (which is perfectly fine stuff), i make it a point to go as low-sodium or no-sodium as possible with the rest of imy ingredients. doing this has ensured that the final product won't be too salty.
i do not think tenderquick or any other cure is absolutely necessary and have been eating beef and wild game jerky all my life with no ill effects. one caveat, however, is that i make my jerky quite dry, not quite rock-hard, but definitely much drier than the "kippered" stuff passsing as jerky these days. i slice my meat thin and make sure it is dry before i remove it from whatever i am making it in.
if you are after moister jerky, then you should use tenderquick and try to cut back on sodium in other places where possible.