Replace Brits with any other faction and the other faction would lose just the same, werh sniper OP. That's all there is to it.
3 rifles with no upgrades < 2 grens + sniper
3 cons < 2 grens + sniper
It depends on skill of course as well, what position they are in, etc.
I agree to some extent, but Sovs and USF are not helpless. A good Rifles or Cons ambush, Oorah or M20 rush are good counters. But UKF, the will bleed too much and the carrier is way behind M20 in terms of combat power.
All I'm saying is, good players can play against a well-microed sniper with Sov or USF (USF is harder though as we all know) but UKF will bleed for a much longer time. Although Ost sniper is somewhat OP as you say, Brits might need better mechanics to counter them early.
I have to add that I mostly played as axis in the alpha since everyone wanted to play UKF at the time I wanted to play, and I abused the hell out of sniper.