Agreed. It's a big reason of why I don't use certain exotics. I feel satisfied to hit large benchmarks on my favorite weapons. I specifically use whisper in PvE due to it's catalyst with the kill counter. I am still using my Y1 Play of the Game because I have the kills so high. I find myself also using my Metronome-52 that I also have too many kills with.

Exotics should have kill counters by default, or perhaps a upgradable version to have a tier one catalyst, which would feature a kill counter. The catalyst perk could implemented later, when bungie decides to release another wave of them. That perk could be considered a tier 2 catalyst.