I've only seen bits and pieces of "Rounders". This movie is definitely an iconic poker flick, but poker has its own romantic qualities. I think what made poker blow up was games like Texas
Hold-em. Games that are relatively easy to learn, difficult to master, and show the "big hands" (full house and up) more often.
Gambling is always interesting. You can turn a small amount of money into a lot with relatively small amounts of skill. Poker is romantic because it is gambling that can be enhanced with smart play and awareness. People look at it as an opportunity to show how smart they are and win money doing it. The movie certainly didn't hurt poker's exposure but I think poker would have grown regardless.