Impossible? I've done it a couple of times these last few days and I rarely play that characater. Anyway, it's your choice if you want to go absolutely full ranged or a hybrid. You get points the closer you are to the battle and you get points by actually doing hits in melee, and unlike most infantry, you're not getting points for either of those. The only source of points you have as a dedicated sniper are your shots. That you want to stay untouchable, out of reach for most of the enemy team is fine, but it just doesn't produce as much points as some other classes, and I find that fine, you're not exactly as valorous as someone being in the fray, are you now?
I agreed that the points for long range sniping is too low, especially considering you'll rarely get any points for being near the actual combat, but a dedicated sniper shouldn't have the same chance of valour as most infantry, at least in my opinion.