But it'll buff critical bursters more than critical single shooters, what won't be good.
Imagine you're 35% (all perks, 10 lk, finesse) critical double shot avenger or gatling.
It means that if you shoot twice, your 1st burst will have 1/3 (35%) that your target will be dead. Second shot will have 2 rolls, 35% because of your critical chance and 35% because of focus. It means you'll have 57.57% that at least 1 roll will succeed and your 2nd burst will kill target if 1st wasn't critical.
As for snipers, their criticals suck so much now, that it won't help, .223 pistol SD better crit vs pijama without any anti-crit perks doing so "much" damage, so that 1st leveled pijama will 1) turn around, look at me and then start laugh or 2) will be knocked out, but still laugh with /e because of ridiculous low damage. Now imagine if he would have anti-crit perk and trait and I had no SD but did normal critical as standard sniper, he wouldn't even notice it, until I'll spend whole magazine on him and then he, may be, die. And if he's not 1st lvl pijama, then I'll need to spend on him so much ammo, that my carry weight won't allow me to carry, moreover he'll need to just stand still and look at me while I'm doing this, damn I better just burst him with any SG I find, it'll be much faster. But it's all off-topic, my main argument is that it'll buff critical bursts, in your post there is no words that it won't work on un-targeted shots, but you mention "snipers" and said nothing about bursts, so if you suggest it to work on bursts too, then it's not good idea. And if they will debuff critical bursts so much, then no one ever will simply do them anymore, as there will be almost no difference between critical and non-critical bursters, except for perk consumption.