The first thing that people should know neither slots or sports, both of them aren't a way to make money.
Don't make it complicated, each person has it's own preference which game he want to gamble, as long as you're interested with the game, you can play any game you like including both of them.
Casino Gambling involves Playing games that are base on luck factor and sometimes our skills also work out in this, it does not involve live event.
I agree, Everyone are allowed to do both, maybe they just need to find out first where they can play or where their personality fits, because there are others who are not fans of sports so when they try sports betting they quickly get bored or lose their momentum, there are those who prefer sports betting because they have a supported team, something like that, no need to choose because it can be tried at the samw time.