From what I see you trade ok ( I hope that doesn't sound patronising). This isn't about persuading anyone who is trading around 70% to ditch their approach and hunt for some 30% approach. What it is about, really, is highlighting the importance of risk management which fills the minds of professional to a far greater extent than amateurs.
I agree, I would not mind having a 70% and I always work towards it but in the mean time I need to work on something is in reach of my ability, mind set and peace of it is essential in my trading and leaving spaces to manoeuvre in errors helps me archive that.