Prologues: Whack, or Bombdiggity?

I get the sense that there's a lot of strong opinions out there about prologues, at least in editorial circles. I don't know how I reached this sense, but it's there none the less, like the Force (which I WILL tap into someday and use to make shit float around my apartment). Some folks (such as my past writing profs) argue that a prologue is a rather useless appendage, something lower quality writers use in lieu of just getting the show on the road and starting the story properly, with Chapter 1. For example:

Prologue
The horse ate a carrot, but still felt uneasy. Something funny was in the air, rolling toward the ranch like a cloud of evil flying monkeys. Something...not so good.

Chapter 1
Harvey looked out the window, watching the horse dig through the garden. He'd always wondered what horses thought about...


Do we really need that foreshadowing first bit? Can't we just start the damn story without it?

It's true there's a lot of misuse of prologues, especially in genre fiction. What I said in my previous post regarding epilogues, making certain they're really necessary, applies to prologues but times a hundred. Readers will read almost any epilogue, no matter how useless or dumb, because they've come a long way, baby, and aren't about to quit now. But a prologue, well, a prologue is a big neon sign at the front of a novel and if they don't like that, you're pretty much screwed straight off. If it's too expositional, too preachy, too foreshadowy, or, worst of all, in fucking italics, they might just slam that book shut right off and never enter your carefully crafted first chapter at all.

And you want to be loved, don't you?

DON'T YOU!?