Plantera wakes up when you kill the Mech bosses because... reasons.
Shadow orbs and Hearts hold muskets, vilethorns and so on in them when you break them open with a hammer, which A: seems as if it would be easier with a saw or an axe and B: why the hell are weapons hanging out in these orbs/hearts anyway?? and for that matter C: miraculously doesn't shatter whatever items are inside the orb/heart.
A sentient murderous plant doesn't mind fighting you underground in the jungle, but gets an inexplicable enraged bonus when moved to a different cavern layer for battle.
The Dryad is completely fine with a Pure or Hallowed world, Nevermind that the jungle and the hallows have arguably the hardest enemies in the game. Shouldn't she suggest a world of just forest or something?
The guide says he will tell you how to survive, and yet gives little functional advice on survival-- most of it revolves around-- go here, check this out, oh look, voodoo doll!! :|
How did any of the NPCs survive if they aren't willing to defend themselves?
The NPCs can't be bothered to settle down themselves, but if you're willing to build their houses for them, they'll be more than happy to live in your home.
If a slime walks in from an open door, everyone walks away from the slime and no one bothers to close the door behind themselves to avoid a slow, humiliating death.
My residents include a nurse, a demolitionist, an arms dealer, a pirate with cannons and an ancient dryad, but no one lifts a finger when I'm in front of them fighting off a werewolf. Or when someone is hurt, the Nurse can't be bothered to help them.
How does killing a giant plant (that has a uncraftable guitar in it) somehow awaken the true inhabitants of the dungeon? P.S. while were talking about dungeon, how can you hold ectoplasm, it is basicly ghost essence.