so it's similiar approach as Dark/Dash's masternodes? Is there really value in this idea?
not at all, Dash master nodes are very special and serves some special purposes.
The point of node rewards is to give incentive to people running nodes, as fees from harvesting
are too low to make it attractive. Additionaly most likely you'll have much bigger chances of
"winning" in this lottery, than chances of harvesting a block.