I don't think Celtics fans hate Horford, I think Boston bandwagon fans do... Horford is a good player, by the time the draft rolled around he was the concensus number 3 I think, he impressed a lot of people when they actually met him and worked him out.
It would have been interesting for a lot of reasons. It probably would have prevented us from being the team we are now. If we pick him and keep him, we don't make the big trades which is big not just for us but because those trades arguably paved the way for the midseason trades in the West (although those may have been more based on the Gasol heist). Plus, instead of the Hawks just swapping picks with us, the Suns would have had the sixth pick, with a choice of guys like Brewer, Noah, Brandan Wright, Jeff Green, etc. Again, who knows what they would have done. Maybe they take Noah and don't make the Shaq trade? Atlanta would have not had a pick and would not be in the playoffs. With our lineup of Al-Al-Pierce-Wally-Rondo, who knows what we would have done. Maybe we'd be the 7th or 8th seed limping in to face Detroit or Orlando (who would have been 1 and 2). Or, maybe Minnesota would have accepted the third pick instead of Al and we would have Al instead of Ray Allen. Maybe Minnesota makes the same deal but instead of us throwing in future picks, we swap last year's 3 for last year's 7, and we still have the pieces for a deal with Seattle. We end up the exact same but Minnesota has Horford and Phoenix has the sixth pick. It's really hard to say. I guess it's interesting, but I'm much happier to be where we are now.
As for the crowd chants when Horford was "embellishing the hurt," Ray Allen smacked him in the face and caught his eye. From what I've seen of Horford, he's not going to embellish his injury. He has too much testosterone to fake injuries, if it wasn't that bad he probably just would have gotten in Ray's face. Dude got caught in the face, it clearly messed with him.
And watching the replay, it didn't look that unintentional by Ray (his eyes seemed to be on Horford's face, not the ball, when he made the play). Honestly, it was probably worse than the flagrant they called on Horford although I understand why the calls went the way they did - Horford was not making a real play on the ball, just making sure the shot didn't get off. It wasn't a hard foul, there was no intent to injure just intent to prevent an and one or an easy layin. Nonetheless, it was early in the game and this series has been escalating, so the refs couldn't take that chance early on. Had the Ray foul been the one in the first quarter, he may have gotten a flagrant for it.
When the Ray thing happened, it was late in the game, the Cs were already up big and Ray appeared at first glance to be strictly going for the ball. No reason for a flagrant call there. If the Hawks made that play it likely would have been viewed as instigation or frustration by a hot-headed young player over a big loss and earned a flagrant but because the Celtics were ahead and Ray is a calm veteran, there's no inferences drawn from the play and no close analysis of it. I'm not saying Ray did it on purpose, but if he did, it was smart - well-timed and innocuous enough not to get a flagrant against him, but hard and directed enough to get a point across, plus there was enough of a cushion with little enough time remaining that it wasn't going to rally the Hawks to a comeback.