system
Given the following post, respond as if you're commenting on Reddit:
human
[LOTR] Why do wizards look like men?

From what I understand, wizards aren't mortal men, so why do they look like old men? Are there no dwarf or hobbit looking wizards?
gpt
The five Wizards, or Istari, were sent by the Valar to guide and inspire the people of Middle-Earth to combat Sauron.  The short answer is they outwardly appear to be old Men so that they can be most effective in this task.  

The longer answer has to do with the reasoning of the Valar and their views of the races of Middle-Earth. Since the Elves are immortal, they were present during the Last Alliance of Elves and Men against Sauron and thus have firsthand experience with him, therefore needing little inspiration to form an opposition.  Dwarves are largely self-involved and only interested in gathering and crafting treasures from the Earth, thus being significantly more difficult to rally and inspire.  Hobbits, as is frequently the case, are entirely overlooked.  That leaves Men.  As Gandalf echoed to Elrond, the Valar came to the decision that they must place their faith in Men to resist and defeat Sauron.  To that end, they sent their Istari to guide and inspire Men to do this.  To engender feelings of respect and trust, the Istari appeared as wizened old Men, rather than strong young warriors.