Not because they are boring, but because they are less addictive than they can be. So they are "boring" in comparison. If we were allowed to use all tricks that mobile and on-line games do it will be really bad for society as it will create more addiction.

It is like Coca-Cola. Even that so much sugar makes it problematic, I find it better that at least does not include cocaine like it did in 1891. Does that make Coca-Cola good? No, it does not. But I find that makes it a lesser evil. Even that cocaine-less Coke is more "boring" nowadays, it is the right thing to do.

I have seen people putting shit ton of money into those machines and they lost easily 100,- Euros per Hour?

I'm sure there is always a white/gray/black thing going on but i do put a slot machine at the very end of black not in gray or white at all.

Coca Cola and the water stealing and the addiction is btw. an additional example for something not that good, it does not make a slot machine any better.