From a human-centric point of view, you are asking yourself why nature beings are humanoid but naked...
But from a god-centric point of view, and conveniently taking as reference we are an Image of God, you should not say a being is humanoid, it is a term used for quick understanding and to aid our minds to get a better picture of the creature.
Also you should consider asking yourself, why and when humans started to use clothes. First reason was protection, then power and belonging. Also envy and jealousy were vital for clothes to evolve into fashion.
The point is you could say nature creatures were also created by god or gods as god-like creatures.
Then they were protected to avoid falling in same temptations as humans, or they are incapable of doing things worth falling in disgrace of god(s), so they had never being taught about embarrasment and inferiority feelings because of being naked. And also they might have tree bark or some other physical protection so they've never felt the desire to artificially protect themselves.
Making things to aid ourselves, to expand our possibilities, to make us feel safe, to counteract our handicaps, those are "human" traits.
A driad capable of understand the above would be sure clothes are a proof that humans are lesser beings.
A wiser driad would understand that human adaptability is a dangerous and/or worth-respect ability.