That is not even considered as gambling if you will invest your bitcoins to casino's even though the risk is there just like gambling games. But that's totally different still that is quite good to say that it is safer to do it than gambling if you want to have some secured profit and avoiding the possible losing of your bitcoins.
But as he said, it is not gambling, it is just like investment when we invest our amount into casino and making profit, and also in this way, less chances to face the lose. So also for me, it is investment way.
Gambling is depend on betting where we play bet and wait the result, and saw suddenly we win or we lose. But it is clear no safe method is here in gambling only for winning.