Or: Why Vanilla quests have totally random starting points.
Want a quest for Utgarde Keep? Run into the instance. Bam, 2/3 quests right there. The last one you get by going along the quest chains at the Horde (Alliance seems to have no equivalent) starting town in the zone.
Nexus? The chains all start about 200 yards from the entrance and take you in a circle around the instance.
Aha, here's a hard one! Halls of Lightning: K3. Weird place, right? Yep. But it's in the same zone and never even leaves it. It's still the same rule of instance quests starting in the zone of the instance. You might have to search a few chains, but it's not going to be far away. There's not much to explore.
Then there's vanilla. Want a quest for WC? Actually, it's in the Barrens. SFK? Silverpine. This isn't proving my point very well.
Want a quest for RFK? It starts in Thunder Bluff. RFD? Undercity.
Sunken Temple? Oh now you just opened a can of worms. Let's see, those start at...
Tanaris. Or is it Ratchet?
Stonard (easy one!)
Hinterlands, in the middle of a troll temple area.
Also Tanaris. And then feralas. Then Tenaris to Zul'Furrak. Back to Hinterlands to a troll temple. Not the same troll temple, a troll city actually. And then back to Tanaris.
Oh, and the extra boss there is from two separate troll temples in Hinterlands, neither of which have been mentioned yet and which you won't be told explicitly to go to by a quest, instead you must read a grey-quality ancient tablet which says how to make the hammer to summon the boss.
Still, it should be admitted that all of the quests in some way related to trolls. Troll artifacts, troll temples, troll quest givers. There's almost a logic to it.
Then there's Scholomance. Did you know that there are two additional bosses that almost no one knows about? That is in addition to the other boss that no one knows about because no one does the dungeon two chains. They're right there, you've probably seen them: Vectus and Marduk Blackpool. They're neutral and don't do much but talk unless you know how to attack them. It's part of a quest.
Where does said quest start? Talk to a goblin. In the Burning Steppes. To explain where that is: nowhere near the Plaguelands. But talk to her and next thing you're on your way to Winterspring to harvest pure cold for some device. Oh, then you inadvertently... I won't spoil it, but let's just say goblins don't care too much who they work for, as long as they get their money.
Quests like these encourage exploration. They make you see that there are links to instances beyond the immediate surroundings. They show you that there is a world here, not just a few disconnected regions. Conspiracies and enemies look so much bigger from the other side of the world. The quests aren't necessary; they're not attunements and the rewards aren't top of the line for any gear level other than bad. Instead they are a reward for the explorer.
Or is it?
Is this vanilla rewarding exploration or is it punishing, very severely, lack of exploration? I'm all for some benefits to explorers, but for the average player WoW should not be a choice between spending days exploring every last corner, a third-party website, or losing out on a lot of lore and potential rewards. Sometimes you'll see a quest like "go talk to X" and it works well for a small reward since these sort of quest aren't actually needed, often you can start the chain at the second person, so the first is just a bonus.