the blockchain reward has to begin with lowest reward, maybe stopped at all and just transaction fee rewards. so that in the endgame when all blocks are mined there will be the ones that most deserved their wealth. at least i would expect that to happen.
If you don't reward early adopters, why should they adopt?
Exactly. Adopters' reward should be risk times time. Early adopters have high risk for longer times, hence, they are rewarded.