Again, not unfair at all if the GM does their job and plays NPCs as sensible people who want to survive.Yeah the discussion on the discord mostly centered around snipers, being used by the players. People felt that talking the time to set up a sniper shot, shooting one bullet and then missing with no chance to suppress was unfair. As stated, it'd be better to roll 1 RoF ammo die and possibly empty the mag to achieve Suppression, and if ammo is scarce that's not ideal.
This is the problem with trying to do simulationism. It will always fail at some point; you end up chasing the goalposts at best or (more likely) breaking the thing that worked in the first place. When instead, you could take advantage of the truly great advantage of TTRPGs: the ability to apply common sense rather than computer thinking to a situation!
As you said, a carefully prepared sniper shot has a pretty good chance of hitting, even at long range, even in dim conditions, even with cover. This is exactly the situation pushing is for! If you still manage to mess all that up, well, maybe you messed it up so much that the bullet doesn't land even close.