I am, at best, ambivalent about this sentiment. Certainly the first sentence should not make people drop the book in disgust, but should the opening be a snare for readers?
I did not choose first sentence in Gods Among Men for others. I wrote the opening over and over, trying one starting point after another, until I finally found a formulation that felt right.
My final choice for the opening sentence introduces my central character and established a starting scene. It leads naturally into a first paragraph crafted to inform the astute reader what to expect from the whole story. The first paragraph is mirrored by the last paragraph of the entire multi-volume epic. Thus Gods Among Men is framed by two paragraphs designed to fit together. They form the beginning and the end, the alpha and omega.
Does my first sentence make readers want to read the second? I don't know. I do know it is the right starting point for the tale I want to tell. I have been told, on more than one occasion, that a different opening might be better. Perhaps, but replacing that paragraph, to me, undermines a structure important to the overall plot.
I can easily replace almost every other sentence or paragraph in Gods Among Men, I can rewrite whole chapters. But the opening paragraph, the opening sentence, is hard to change without disrupting something fundamental to the story.