You need to remember if you do this then the block chain size will increase and so will the required bandwidth. So what will happen is that it will take more resources to secure the network by node operators. Eventually the resources will be too much so node operators would stop providing the service.
The block size and reward would be reduced by 2x (or multiplied by 0.5), and halving time amount of blocks (to halving still happen every 4 years, despise faster blocks).