I've alrready responded in a smiliar question.

There is no hard cap because a hard cap is completly useless, with a hard cap on amount of coins, miners will stop mining when the block reward drop to zero, the fees are not enough to sustain the amount of miners.
That's why there is a voting system, it's better than a hard fork every month to change the block reward, and it is the community that decides, this is rightful.

At the bitcoin conference.
"As block rewards reduce in size, transaction payments may not be sufficient to support the ever-increasing mining costs. This could result in the need to resort to a constant block reward for perpetuity in order to compensate miners appropriately."