When a pitcher suffers from a large deviation in his batting average on balls in play (BABIP), we are typically good at not faulting him for it. Sometimes there are rumblings that perhaps this particular pitcher does not conform to the standard model because of such-and-so reason, but largely most of those criticisms are reactionary and overzealous. Trying to establish meaning where usually there is none. Fluctuations happen and there's not much we can do about them other than do our best to recognize when they are not predictive.
Hitters, on the other hand, do exert more repeatable control over their BABIP. That's important to know, but it is also important to know that they do not wield absolute control over it either. Hitters are also susceptible to random variance in their ball in play average and we don't tend to acknowledge that as frequently. That's a mistake because we should always be diligent about fighting our own biases.
And that is why I am not yet too worried about Ichiro or convinced of everlasting impotence at the plate. If I regress Ichiro's average on his batted to his recent historical marks, his triple slash numbers would look like .294/.353/.346 and I doubt that Ichiro would be generating much worry if he had that hitting line. That would be an almost perfectly league average wOBA.
I am not saying that Ichiro deserves to be hitting .304. Not all changes in BABIP are flukes. There are valid reasons for it to get better or worse. What I am saying is that rarely is the entire change attributable to getting better or worse. Ichiro may be finally declining, but it is highly unlikely that the beginning of that decline would see his BABIP drop from .336 (April) to .214 (May). Maybe 10-15% of that drop could be legitimately the result of Ichiro aging, or not adjusting to more inside pitches or whatever. However, the vast majority is probably just plain bad luck.