Ranger is like every class, there are good and bad ones.
That screenshot doesn't show if those rangers are good or not.
I know a lot of rangers who score very very good on k/d but are totally worthless, I would pay actually not to have them in my group.
But everyone is free to play as he likes of course.
The only ranger I really like on Crom tbh is Davijr (there are also few more good, like Memshur and a couple more I don't remember names).
Good player doesn't leave mini or go afk after 2 deaths (Throughtedoor / Kingkozak style), but is hard to have people understand that.
Must be really great satisfaction to play classes like demo or ranger for k/d only.. it's so hard to get kills.. lol
But the same applies to every class, if you play only easy mode minis on every class someone can have very high k/d.
Pointless.