The point of Open isn't to be a gravestone to PVP. It's so that random people can have the possiblity to meet other random people who are likely but not guaranteed to be awesome. A few psychopath paths a year sprinkled in are like adding salt to the broth, bringing out the flavor. No psychos = tasteless gruel. And 100% psychos would just be a pile of salt.
That's a purely subjective view, though, and nothing about the introduction of Open PvE would lead to 100% psychos in Open PvP, unless you're going to claim that everybody who interdicts others is a pyschopath, which seems somewhat counter to everything active-PvP players have argued.
If all your losing is those who don't wish to engage you in PvP anyway, and as such are likely to either put up almost no fight and die, run away, or clog, then what value is lost?