Long before poker came to be, cards and gambling already had achieved considerable notoriety. Just as the first version of the game appearing in the American south in the early 1800s combined elements of other card games, so, too, did poker inherit from those earlier games a kind of outlaw status right from the very start.
Poker was dangerous. Unsafe. Of uncertain legality. A threat to individuals and perhaps society as a whole. At best an idle waste of time and at worst a way to lose whatever you were willing to risk in the game and maybe even more than that.