You think that just because a coin is mined it is 'hard' and has wrought physical value, but this wrong on a couple of points.
- 1. The miner may sell that coin at a loss.
- 2. As the price comes down and miners drop off the network, the difficulty in creating new supply also decreases.
Whether the miner sells coin at a loss or not is irrelevant because they had to buy it first. The masternode didn't.
So if miners sell at a lost the net investment in the network is positive. If a masternode sells at a profit the net investment in the network is negative.
That's what matters - the sums. The more you move the reward towards masternodes, the less outside investment gets into the network and the more reward has to be paid out of existing marketcap rather than outside investment.