Casino owners do not design their games to empty their pockets, but to do business. Think about it, if seven out of ten casino owners lost, would this casino still be in business? But if you ask ten gamblers, seven of them will say that they lost. Just as not all gamblers lose, not all casino owners make a profit. Just as there are two sides to a coin.
And the one who said that a machine in the casino went bad and the casino owner lost a lot of money is completely their fault. Just imagine if the glitch in this machine had been the other way around. If the casino had lost the user instead of the user, then this news would never have come to anyone's attention. So it is their responsibility to always maintain their machines properly.
Yeah, you are absolutely true! In the short term casinos could afford to absorb those losses when someone is on a hot streak, like as another user already said above your post- building a streak on roulette, however that is simply a short-term fluctuation of the dice. In the long term the house edge ensures that they recuperate these losses & more. It is like slicing out small parts slowly over a period of time, big wins may happen now and then but maths will always prevail.