That isn't necessarily the case. WC3C is just more bent on critical review and catering to users that truly want to improve as a WC3 modder. If you want to get better, WC3C is the place to go, if you just want to be loved, the Hive is there for that. I've tried to give legitimate feedback here in the past, and its only met with opposition from the vast majority, so I've since given up trying.
As a result of these differences in both community and style, people misinterpret WC3C's case as 'elitist' and mistake the Hive's case as 'idiotic.' Neither of these stereotypes are true, really, but because so many people believe everything they hear they persist. If the sites were to ever 'get along' so to speak, you'd have to change the attitudes of hundreds of users. That won't happen, though, so I doubt an affiliation will ever be possible.