Now of course, if there's something that appeals to me, I don't quibble. But there are a couple things that make me think that probably the writer doesn't have an "inner ear"--
--Too many names on the first page-- introducing too many characters.
--A clumsily long opening sentence that tries to tell all right away. I like some establishing in the first page, but I really am willing to read a whole page to get it. :)
-- A fake action opening where it's not clear who is involved or how.
-- Unclear POV-- who are we, and what does that mean? Use your point of view approach wisely. If you are starting inside the point of view of the character, then start INSIDE, not outside. That is, give some quick glimpse into who this is mentally. But if you're starting with an omniscient (outside) POV, for goodness sake, use it wisely-- and that's a quick setting establishment or a cultural observation. Think seriously what the opening tells the reader. Don't start with dialogue just because that's trendy. Read the opening of books you admire, and think about the effect on you, and think about the effect you want to have on your reader.
-- Awkwardness. Remember, I'm an editor. That means I am -very- sensitive to language. I will read on regardless, but if your first sentence has a typo, a grammatical error, or an awkward usage, then I'm going to be watching for problems in the paragraphs to come-- that is, I'm going to assess what comes in a jaundiced viewpoint. Don't make your friends read the whole book... but have lots read the first paragraph. :)
-- Trendy openings. Don't be trendy. Whatever the latest trend in openings is, it's probably not right for your book, because it didn't evolve from your book. Again, what do you want your readers to know at the very start? Make it as sharp and interesting as you can-- but make it yours.