The answer is simple: 'sometimes'.
If you have a situation where the entire premise of the book changes from the intro, and where that premise is almost a completely separate sub-story, then yes... for instance, I had a character from another world, whose world got destroyed. Her biology, world, and basic understanding were utterly alien, and then she arrived as a human with zero understanding of humanity. In that case, a prologue chapter with the 'mini story' of her world's destruction is absolutely critical. I could make it chapter 1, but it's self-contained.
Basically, it all comes down to the artist's touch and the needs of the story. I have read some prologues even by successful authors that were absolutely awful digressions that ruined the book, but some (like Fred Saberhagen's) that were NECESSARY for the story.
But, in general, prologues suck when the writing sucks.