I love PVP, but I don't just go around and attack people at random, I'll only attack people for (reasons) and I will generally not kill them unless that's part of the reason.
Couple reasons I attack people.
To steal cargo (yep, I am fully aware there are faster and better ways to make money, but I find this fun. I carry cargo scanner, FSD wake scanner, hatch breakers and collectors when being a pirate)
If they attacked me. Even in this case, I'll generally try to disable people instead of destroy them, though I would like it if there were more methods of doing this more reliably, missiles are really useful for this now though and a massivly welcome change.
Power play reasons (though I am not a big fan of power play, it does give legitamate reasons for battles) Again, here I tend to disable if I can, because I just find that more fun.
If I am for/against a CG, or a side of a CG. So, say someone is attacking people to stop them completing a CG I am for, I'll attack these guys trying to stop it.
Of if I am against a CG (this is normally only when the few occasions where a CG has more than one side to it) then I'll attack people to stop them achieving their side of it. In these cases I'll kill, unless removing their cargo achieves my actual goal.
Other in game reasons (for instance, and this is going to at first sound like I'm a horrible person, bear with me) Interdicting newbs....
But I'll interdict them, and force them to scoop up some imperial slaves, and smuggle them into the nearest federation station/outpost with a black market so they can "infiltrate" it or some other made up reason. It's generally fun for me, them, and also teaches the newb about cargo scooping, smuggling, black markets, interdiction and other players being able to interdict you, and the imperial slaves commodity, as well as at the least, the federation and the empire.
So yeah, I love PvP, but I need reasons, which can be found.