He’s the #14 most dangerous NPC in Hardcore (according to Deathlog), and he’s a quest objective, and he casts cat form on himself, hits very hard and fast, and pulls with other mobs in a cave he’s in, full of hyperspawns.
He’s just slightly less dangerous than Gazz’uz, and I see people dying to Gazz’uz in Skull Rock pretty much every five minutes or less.
People simply prefer the other locations as they’re closer to everything they’re normally used it. The #1 race in Alliance is Human by a lot so that gives you more or less an idea of where people are at.
Melenas is a lot easier if you do the quest that gives you the on use item that reduces melee damage of a target by 5. Gazz is only tough because he’s a lvl 14 mob in a cave where the rest of the mobs are 9-11.
Especially in hardcore “zone-hopping” is extremely beneficial and a good idea. Whether I am starting in Elwynn or Dun Morogh I always do quests in both to get ahead on levels. In Teldrassil you don’t have access to the tram and the only boat takes you to a level 20+ zone. If you don’t want to swim, portal/summon or “run the wetlands gauntlet” you are pretty much prevented from zone hopping until after you finish Darkshore.
Also both Teldrassil and Darkshore are very inconveniently laid out zones in comparison to Ewlynn/Dun Morogh & Westfall/Loch Modan respectively.