The game is much more balanced now (char/class wise).
Cabals more balanced as well now.

The IMMs monitor perma grouping much more now (no more Palan/Jagr, Arolin/Zharradam and the like) gangbanging permagroups. Or, they just have to watch their asses more now.

Over abundance of protections make people more careless and can make people take chances they normally would not, leading to death.

IRC groups have made info dissemination too rampant, therefore people are used to getting spoon fed info and items. They become equipped like a God but they couldn't PK their way out of a paper bag which takes years of experience to really excel at (there really is no substitute for actual experience in pking). I actualy like this because it makes that equipment all the more easy for me to acquire. People have started to rely on equipment to PK, not their own skills. Look at all the shifters. All they are gonna learn is the location of a few a/b/s and flyto/murder. You aren't gonna learn natural pk talent that way.

The weak players gravitate to larger cabals where gangbanging is the norm. Here, they don't learn independence, they just learn how to spam (insert lagging attack here) while the few competent ones lead the group.

I think there will always be some skilled Pkers who rely on themselves, not others (eg. Manarie, Drucyrus, Loborguz) but by far, most people are content to gangbang. I think several years ago, the same ratio still existed, only the gangbangers were more rampant back then due to lack of monitoring of the permas by the Imms and OOC stuff went pretty well unchecked. The result, obliterated pk ranges whenever one of these groups would log in together. This doesn't happen as much today so maybe that is why the body count may be lower today.

Finally, distention is a huge factor in reducing pking. Most people lean how to pk at the low ranks and then progress to the midranks. With this pking now effectively capped, people will find themselves at hero with significantly fewer successful pk's than in the past. Result: less battle experienced heros.

Of course, continuously making new charcaters and pking with them can get around this but I am not sure many people are willing to put in the time to keep making new characters and practice their stuff up just so they can distend badly and delete.

Perhaps these are a few reasons for the seemingly pk inept hero range today.