It depends which fans of SF and from what cultural background you're talking about. I've met many people who would define themselves as big readers of SF who can't abide any of Card's fiction, writing (and much less, his opinions). Very liberal/progressive leaning people in particular have fairly little love for Card or his novels, even Ender's Game. I would say he's way too controversial with some crowds at least, to be qualified as "universally loved" (there's also the fact a fair percentage of SF readers find the Ender series fairly light weight compared to the works of say, someone like Frank Herbert).

Same for Robin Hobb. Unlike Card she doesn't generate much in terms of heated debates (I never met convinced Hobb haters, at least), but I for one never liked (not even finished) any of her novels and I know many who simply ignore her novels, either because they've tried and didn't like it like me, or because friends who know their tastes in Fantasy recommended they skip Hobb (I wouldn't exactly recommend Hobb to anyone who tell me their ideal fantasy writer is someone like Steven Erikson or Bakker, for example).

I don't think there's any work that makes unanimity in Fantasy or SF, no more than there really is in other genres. Even among the established classics, you need to go quite a bit back in time before you come across works which importance is anything like universally appreciated (let alone close to universally loved) .