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.
Your only argument could be the licensing because if it is for the other option which is security, I do not see any reason why a slot machine cannot be placed in a public place. If an ATM machine that has money in it for dispensing can be in a public place, slot machine can be there also.
Do you really want to defend your answer by comparing an ATM to a slot machine and why it should be placed in public spaces soon? I guess you are not getting it. I have already mentioned that it's not viable. Just think about it: slot machines were invented in 1894, and if it were possible to place them in areas where you think they should be, that would have happened a long time ago.