In the 1800s, ten-pin bowling was invented as a way to circumvent the ban on nine-pin bowling that was placed by all states except Texas. However, ten-pin bowling was not banned by any state. I don't see any difference in the two sports other than the number of pins and a few minor differences in the rules and equipment, so I think any reason applicable to one should be applicable. Why wasn't ten-pin bowling banned, for the same reasons as nine-pin bowling? If the reasons were no longer applicable after ten-pin bowling was invented, why didn't most states re-allow nine-pin bowling?
My reference is this video, and the part of it that applies to this question starts at 4:39 and ends at 4:59:
When the game made its way over to America, nine-pin bowling was banned because it promoted gambling. The legend goes that people cleverly came up with ten-pin bowling to get around the law. Whoa, totally different game. Today in the US, nine-pin bowling is only played in Texas because it was the one state that didn't ban it, instead charging it tax.