Most people I've known who "hate" it stop hating it after I sit down with them for five minutes and just show them how to use it and make it work like they want it to.
Every time I use an Office 2007+ machine I have to re-learn how to use the damn thing. I use a lot of different software and somehow I can still remember how to use it even going months or years between uses, but for some reason I cannot do that with the Office ribbon interface. However, my main compliant about the ribbon really has to do with that it doesn't tell you what the shortcut keys are. All sane software for the past decade has had this nifty menu system that tells you exactly what shortcut to use for each operation, why exactly is it more convenient to force me to use the help to find the shortcut keys?