As I understand most the "Hal hate", it generally stemmed from the fact he was given so little personality over the years and it's only recently they've really established him.
The problem had been that with each new Green Lantern they introduced in the comics who had a very distinct and interesting personality, especially the newer Earth-born Lanterns, Hal seemed very small comparatively. In the comics, during the Silver Age and even into the Bronze Age, they just made him more and more aloof instead of fleshing out his personality.
I'm almost inclined to say over the years, he's absorbed a little bit of what made Gardner, Stewart and Rayner special somewhat through osmosis but various writers have taken and made what the qualities are about him distinctly different.
For instance, when I broke down my analysis of Hal in the movie, I said there's a lot of times he came off like Rayner (thanks to those of you guys validating me on this). I can see where those of you saying they see Gardner in him too, but over the years, Hal was built up to be a hot head too, like Gardner, just not the same kind of hot head. Gardner is that hot head that doesn't know when back down and will rush into danger not caring how dangerous it is. Hal on the other hand is hot headed enough to rush into danger, but he's culpable enough to know the perils and likes living on the edge; but he knows when he has to backdown and regroup. Guy would rather keep bashing something till it dies regardless if said bashing is actually having an effect or not where Hal would realize that said bashing isn't making progress. I mean being the first one rushing in to take a swing at Darkseid and then getting sent into a wall; I won't deny, that's classic Guy --- but I also didn't think it was too much of a stretch for Hal, though maybe it was. A "good" Hal (that is to say a well executed Hal) probably would have let Superman
take the first swing, but this could also be a very green (pun intended) Hal Jordan we're playing with too; he may have only gotten his ring two weeks ago.