It's said about brain that, "use it or lose it" — now, question being, do you think if person plays brainless gambling games such as slots, dice for major part of his/her daily routine, will it make him/her dull?
Edit: "brainless" as in playing gambling games that does not require using brain, I thought it was clear especially given examples.
I wouldn't call any gambling games brainless because money is involved, even if it's games like slot that totally depends on luck to win. A gambler that is playing casino games with their money surely wants to test their luck and to receive reward or winnings if it favors them. I don't even think that it's necessary to apply too much brain work in gambling because after all your supposed perfect strategy and analysis you can still lose your bet. The thing is that people should not see gambling as a job, enjoy yourself with amount that you can afford to loose, no need to stress your brain so much because of gambling.