Because the people who want to call Palin a fool need advance notice to get enough of them together in one place to be sufficiently disruptive, and they need the media there to document it if Palin's supporters give them the ass-kicking they deserve, is why. The media can follow her around, but they don't know where she will stop.
And there's the problem. Because to get the requisite number of filthy winos, jejune kids, and aging hippies to any of these stops would entail having nine or ten tour buses full of these fools follow her around and be in a constant state of readiness to jump off and start screaming puerile slogans at her and shout her down. It isn't just impractical, it's impossible to get the slackers that make up these phony mobs to discipline themselves to be ready to act at a moment's notice, with zero time to work up some courage before they start in with their harassment.
And even if they did manage to organize that well, the resulting caravan would soon be noticed by local media and - oh, say - FOX News, and the thug tactics being used would be plainly exposed.
And so Palin is met by adoring crowds everywhere she goes; and the poor rent-a-protesters can't send in an advance mob to make it appear that she is the vilest, most hated person in America.
It drives them NUTS-O!!
Good work, Governor Palin. You go, Girl!