It's a good idea but won't happen (at least not anytime soon). Anet already removed expertise amulets from pvp (deadshot, wanderer, viper, etc.) and the chances of them rebalancing them and adding them to the game are minimal, especially while EoD is taking up their time. Making condi builds take expertise would force them to give up condi damage and avoid condi burst builds, which go against the damage over time philosophy that condis were supposed to follow.
On scourge, I think it has its own set of issues related to its class design and I don't think an amulet change would fix that, but at least it might help.