I'll concede the first clip. I think it should be harder to land sniper shots under fire, but sure, skill + luck should get you a kill in encounters like that.

But, for the other two clips, I think it is a very serious problem. In my opinion, a long range precision weapon should not be getting one shot kills an instant after being hit by a point blank charged melee. Should not be getting kills after walking through a grenade + gunfire. I don't think there should be any amount of skill and luck that corrects for what happened in the second and third clip. At some point choosing to stick with the wrong weapon for a situation should mean you're out of luck. Wading through enough enemy firepower to knock you to a sliver of health in an instant while trying to aim a precision weapon should mean your aim is thrown completely off and you lose.

Making the wrong decisions and being outplayed should have consequences.

Instead, with the way things are right now, there is a good chance that there are no consequences. That you win despite everything going against you. It's not like snap sniper shots while under fire or at a bad range are uncommon in Destiny. Those three clips certainly weren't the only three times that play session I felt I outplayed an enemy sniper (sometimes significantly like in clip 2 and 3) but still lost.

I think either powerful attacks need to throw off scoped snipers drastically more, or perhaps attacks like grenades and charged melees, and other attacks that critically injure you in one hit (like a non-fatal shotgun or fatal fusion rifle blast, or a near miss with a rocket) should disable the precision damage of sniper rifles for a short time to make sure it is impossible to immediately no-scope someone who is at full health.

I am in full agreement with you Raga. I think there really needs to be done to snipers. I have also had many cases where I'm pumping a guy with PR in the face, but right before he dies he gets a head shot off? And yes this was at mid to short range. That should never happen unless you are incredibly lucky. Personally, if I had my choice, I would make it so that snipers are nearly unusable when under constant fire. So that if you are using anything faster than a Scout Rifle renders a sniper useless if you are hitting them. That means that a sniper duel can still be had without rendering the first person hit with a sniper useless.

Maybe I'm being a little drastic, but I feel like snipers should be used for what they were designed for, covertly killing people without them knowing. Not to be used as a front line weapon against close ranged weapons. But really, that's just me.