Why not just countersnipe?
2 main reasons:
Easier said than done; good players will always screen their sniper and not overextend (especially now with the sight range nerf). If there's a 222 on the field still and he's running a commander with recon the task becomes even more daunting.
By the time you're in a position to safely get out a sniper (we're talking after AEC) you've already bled a ton of MP and likely lost some territory since 4-man sections with their slow reinforce time and 28MP model cost are really gimped by even a single snipe (25% of DPS lost).
That being said, sometimes it's the only option (other than Commando ambushes, which are even less consistent).