This is going to sound weird, but I don’t think you currently lose PVP points for a defense loss. I’ve watched my losses counter go from 30-ish to 55, and I haven’t lost a single PVP point. I think you lose points for defense wins – I have only two defense victories, and also only two lines in my log show me losing points.
So, once again, it may be more effective to set weak defense teams. 