because every mining is uselss and full of loss and full of risk . there is always a chance to ran away the mining site any time without notice . hashocean mining is a best example of you topic that you have started .
Mining is not meant to be doing virtually without any hardware of your own,hashocean was a cloud mining site who aimed at scamming people and there are good cloud mining site,but it is not worth investing at this time.
Mining has its own risk and you cant be a casual miner and think of earning a profit,first off you have to invest heavily for the ASIC miners if you are planning to make minning a profitable business or you can plan on mining alt coins which is less expensive than bitcoin mining.