The last two years there was a constant excuse that the Dodgers and Braves weren't built for the playoffs. Now that the Phillies are struggling, despite being awesome in the playoffs the last two years, it really starts to give credibility to the idea that this playoff format is simply putting the best teams at a disadvantage. If it happens to the Yankees, you've just pissed off the biggest fanbase in your league.
But most importantly, last year's "World Series", which pitted the MLB's 7th best team against it's 13th best team, had the lowest ratings since TV ratings records began. The same thing will happen if you get a bunch of wildcard teams playing in the CS and WS this year. The TV ratings will basically demand that MLB change the playoff structure.