kind of wrong. maybe you perceive it that way because it was changed to be a “mostly” horde zone in cataclysm. during vanilla most of the eastern kingdoms, in general, is heavily alliance based. southshore had as many if not more quests than tarren mill and southshore was the closest lowbie flight path to scarlet monestary(unless you make the trek to eastern plaguelands flightpath and then run the gauntlet through the lvl 50ish mobs to get to the level 30ish dungeon… so you had constant teams of level 30-40 alliance players flying to southshore to make the run up to scarlet monestary, usually right by tarren mill and up through silverpine, right by the sepulcher(unless they were lucky to have water walking)
there were also group quests involving patrolling npcs between hillsbrad and arathi highlands and the necromancer quest that literally sent horde players into the alliance town of southshore to summon an elite npc that attacks the town, which almost always instigated a fight.
ironically one of the best unintendedly designed pvp zones in classic wow.