The first World Series was held in 1903, but that was a best of 9 series. The next World Series was held in 1905, and from 1905 through 1918 the World Series was a best of 7 series. Between 1905-1918, 6 of the series went to at least 6 games. Then, in 1919, baseball decided to go back to a best of 9 series like they had used in the first World Series, in an attempt to generate more interest and more revenue. After three seasons of this the powers that be deemed a 7 game series more appropriate, and that's the format that's been used since. There was no World Series played in the strike-shortened 1994 season. Here's the official numbers on the World Series' that have gone to game 6 in history:
1905-1918: 6/14 series had a game 6
1922-2010: 52/88 series had a game 6
That means that among 102 World Series that were of the best-of-seven format, 58 of them have gone to at least 6 games. That's a remarkable 57% of the series, and it's happened over 100 years, so it's difficult to say it's a random fluke. Karl Ravech's comment that "You don't get a lot of game 6's" was clearly wrong. I like Ravech and don't mean to criticize him, but it shows that the way analysts and announcers try to hype games up is more important than what is actually said. By making game 6's seem rare, it makes the situation seem bigger. Ravech isn't trying to purposely mislead the viewer; if anything he's trying to mislead himself because he's so invested in the game itself. He may not care who wins, but he's spent days and nights covering baseball for the past 7 months, so this game is huge to him.
What's more surprising is recent history. Maybe that's what misled Ravech into thinking that we don't see a lot of game 6's; from 2004-2010 there's been just one World Series that went to six games, and that was in 2009 when the Yankees beat the Phillies in 6. It's almost certain that this is just an example of a small-sample size creating a fluke in the data, but it's interesting nonetheless. So despite the experts best efforts to prove that game 6 was indeed a "big sports moment" and something that doesn't happen all that often, the fact is you're going to see a game 6 two out of every four years on average, so if Rangers-Cardinals isn't your cup of tea, you can probably just wait until next year and watch two different teams in a game 6. You have about a 57% chance.