Really? Why compare it to an ATM? That doesn’t even make sense. An ATM gives you cash, while a slot machine eats your cash. Totally opposite ... 
You miss the point completely. There's no comparing ATMs and Slot machines, OP was simply stating how they're simar in this context.
When ATMs first started, they were only installed outside the banks, then with time, they spread to different public places. Now you have ATMs in malls, train station, bus stations and even parks.
SO I think the OP is right to ask if we would see this trend extended to Slot machines that are usually seen in Casinos alone. Maybe with time you can seein them in other places that arent casinos like resturnts, bars, night clubs and similar places.
If it would be possible to have slot machines in these places, then I don't see a problem.
I guess I can finally understand the OP’s point now, sorry for the quick reaction, @OP.
But I still don’t get why that idea even came up.
It’s just not feasible to install these machines in public places like malls and train stations.
First, gambling is heavily regulated, and these machines can only be in places with a licensed gambling operator. Security is a huge factor also, if these machines can still be tampered with in a casino, where there are tons of cameras, imagine putting them in public areas. It’s just not viable. Forget about it.