This is a must-read article at South Side Sox, ostensibly about the White Sox's offensive struggles but in a larger sense it's about why (and how) professional baseball players are a lot more like robots than are regular folk.
In any case, when we say things like "randomness" and "revert to the mean" it's because there's a disconnect between the underlying fundamentals and the actual results. Many saber commentators will just leave it at that. Eventually, things will get back on track because we've seen that's what tends to happen given enough time. And I do have faith that this is true. These guys are professionals just like all the other MLBers. They'll get it going.
Anyway, the implicit saber model is that these guys are nearly machines when it comes to athletic performance that whatever the weaknesses of the flesh exist, they'll soon by cancelled out. As it turns out, there's scientific research that backs this understanding of the athletic-performer-as-robot. Thanks to Malcolm Gladwell, most folks have heard about the 10,000 hour rule. As in, that's how long it takes to get really, really good at it. Whatever "it" it is.