Then again to get hardline with the -1 and reroll you are giving up other valuable perk2 options. So its a trade off. You can choose a helper in getting streaks. Or you can get immunity to betties, helicopters, sentryguns, and no target markers. Or more power to get kills with one shot for lower powered weapons, especially those with silencers. Its up to you which you think is more valuable. Do you want enhanced combat abilities or a little easier time to get a streak?
There are plenty of counters to all streak weapons. If you are concerned about more helicopters, ac130s and artillery get a SAM at 4-kills. Or 3 with hardline. Assuming a clear line of sight they are pretty much a guaranteed kill every time. And lets not forget you can steal cp's. You see the green smoke. You know its coming. Wait for someone to try and take it then shoot his ass. And if you have hacker you can leave the enemy a decoy for their troubles.
If you look at all these counters streaks are not nearly as deadly as you think... if the team chooses to do it.