Common man. The series wasn't won/lost on that single incident. Agreed; let's just say that Horry was out of line. But heck, they played them at full strength for 5 games! The Spurs beat them 4-2 on that playoff series. Even during the regular season, you cannot claim that the Suns have the Spurs' number. We've seen more harder fouls during that season playoffs but we don't see the fans "whining" about it. In fact, we've seen harder fouls in past games but yet why don't we see those fans whining...
Game 5 was very critical and was the turning point of the series. Phoenix might have played in complete cast for 5 games but the question is, will it be same if Amare Stoudemire and Boris Diaw was on Game 5? What if there was still a Game 7, is the Spurs sure of winning it? San Antonio was really having a hard time dealing with Steve Nash during that series and even though they are that strong, they still weren't able to break lose until Robert Horry hacked Nash.
It's not whining, it's all about being fair. Hard fouls are different from those which are done intentionally. I bet the Lakers fans would also react that way if Kobe Bryant was suspended after Raja Bell hit him with a clothesline.