I would agree with you over the short term, however there does not appear to be very many risks to the company once the miners are sold so if they are trying to be in business over the long term it would likely be more profitable to act honestly.
If they were acting honestly it would be trivial for them to provide more proof as a way to bolster their reputation and advertise their product. Whether or not there are risks for them purchasing ASICs(I contend there are many) is a moot point because my concerns lie with the motivations being much stronger based upon the much higher profitability of running a fractional ponzi scheme than actually investing and maintaining ASIC's which quickly lose their value.
You should remember that some of their users have received payments that have exceed the cost of their miners.
Sure, it is hypothetically possible to turn a profit cloud mining, just like its is possible to win at gambling in Las Vegas. I would contend that gambling in a regulated Casino in Vegas is a better investment than cloud mining however. Proving thus is simply a matter of comparing casino 95-98% payouts to the average ROI of a person cloud mining.