I personally view leaderboards as temporary data which represents those who are currently participating in the 'competitive' environment. I don't even think that it needs to be rewarded, being listed is enough IMO. Fp4 thinks differently, so you should thank him for that!
However, we both agree that the permanency of your efforts comes in the stats that are forever displayed in your profile. Having a head start of several years doesn't mean that you were any better in the activity than someone of today, it just literally means that you had a head start. This is lessened by the fact that we are now dealing with specific, quantifiable time periods. I understand the notion of 'All Time' boards offering personal milestones to reach, but this effect can be supplemented by an achievements system.