^ This.
There is a well known hardcore republic PvP team on EU Progenitor, and I see at least 3 Imp people quit as soon as they see them. It infuriates me, because it all it does is hand an easy win - and easy WH gear - to that team...
As a healer like me, you enter a WZ depending on your team to perform. You can perhaps solo 1 guy - it will take you a while as a 31 point healer, but possible nonetheless and cap a base, but that's about the limit of the impact you can perform outside of your main role healing your team.
Introduce deserter debuff. And make it harsh - at least 30 minutes.