Virus Weapons are useless. By the time you drain enough Will, pretty much any other weapon could have killed them 5 times over. You also need to break through armor which might make sense but simply makes it completely impractical.
The only thing I thought might be useful was to weaken them prior to mind control - but since panicking enemies keep panicking even if you control them this does not work either.
Rush kill tend push rush forward, it’s not the only way to manage it.
In a more cautious and slower approach virus can be very useful against big targets, still pointless against smaller target than tend have a too high pool of Will and aren’t enough special target to make virus significant.
I suppose that dev problem is find a good balance between useful and OP. I would tend agree with you that it shouldn’t require go through armor, it’s not isolation armor, it’s not that much unrealistic, it could also spread a gaz.
With the special skill adding 1 virus per bullets, two bursts with all bullets hitting it’s 24 Virus. But hardly with a basic build to be very practical. You’ll need either use stealth either increase precision to get something really useful.
The Rifle will allow increase virus from a longer range but slower.
And then you have the multi shot options, Adrenalin Rush or Rage Bust. With those the AR and even more the SR will allow ensure high virus charge rather fast.
There’s also the option to increase precision option with Quick Shot.
At end, it’s a slower tool, perhaps it can be boost a bit, but without rush it is rather powerful for some targets. And it’s not just about control, but also about disabling any special action.