Why won't the Yankees win the World Series this year?

Every year the Yankee fans, and owner, think the Yankees will win it all. Besides being disappointed in the end if it doesn't happen, the fans really are some of the best in the game. They are usually very optomistic, and know the players well. So my question is looking at the dark side, and wondering what will cause them to lose. Will it be injury, bad performance, better performance by another team, bad managing, bad trades, A-Rod's playoff woes, whatever. I'm just curious if the Bronx faithful will indulge me on this one. And just so you know, I'm an Astros fan so I've got a long list why my team won't. Not that I'm counting them out. I just see Yankee fans everywhere I go.