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.