Yes it is true every time. I am yet see proof of someone who earned more through CM(without referral bonus) than holding, in the same period of time. Difficulty decrease is such a rare occasion that you wont able to notice it in a 12 month contract. When you did your calculation, you wouldnt have considered the difficulty increase. It is the main criteria which cannot be predicted. Also you should not calculate it in dollar value instead the relative coin count/price on the day you bought the contract.
Say for example, in 2017, a 1500 dollar hashflare investment would have returned $4300 by the end. But the same investment directly in bitcoin, would have returned $19,600. This is always the case with cloud mining. Cloud mining would always give lesser profit than Buying and holding.