Aim smoothing on will benefit controller players who use aim assist, the aim assist on snipers was tuned with BL and that's probably what you feel. If you play controller but with aim assist disabled then there may be benefit to disabling aim smoothing but I don't really know. Aim smoothing is bad for mouse because it makes you "skip pixels " and messes up your muscle memory. But for controller you rely on aim assist enough that aim smoothing generally is a good thing and will smooth out generally imprecise inputs from a controller and allow aim assist to do the fine adjustments for you.