If you are making enough through mining, like massive mining rigs with good power rates then you can live of that. Or if you are good at trading and have good capital then you can also go about it that way.
I think mining is just a temporary earning since difficulty become harder each day. Unless we buy another set of miners, we won't be able to compete against other miners who have lots of hashing power. Even when we are participating in a pool, if we do not increase our hashing power, the BTC we earn as share from the pool is decreasing. Trading on the other hand is quite good. The longer we trade, the better we are since we will learn from the experience we received in trading. Both needs a good capital but I think trading would give us a better source of income if we grasp the needed skills and knowledge on how to be successful on it.