Why take away a perfectly legitamate style of pking and defense? Killing yourself has its place, and I think that it's actually a more skillful part of pking.
My advice to beating it
Get good at chasing people so they can't bomb themselves. Even at sards you can protect the door and swing when they try and leave. Even the lantern+bomb can be easily beaten by a good chaser, as they lose their blink when they place the bomb. This isn't a issue with the game, if anything it makes pking more interesting and exciting.
if someone is on my bad side I will SD so they will never kill me. Sometimes ill do it just for practice. Hell, some days I'll just feel like it and do it. Do I feel bad for "robbing" you of a kill? Not at all, because if you weren't good enough to stop my suicide then you didn't deserve to kill me.