In a way, I think the monster lacking a name is like schools that attempt to make their students wear uniforms: the idea is that students will display their creativity in their work, rather than by what they wear. I think by not giving the monster a name, it allows his appearance and behavior to get the full attention of the reader, and it helps avoid what happens in so many other novels, where the character's name is in some way indicative of what the character is, or stands for.
The monster has no name in the novel. It has been said that this omission is a reflection of Victor Frankenstein's complete rejection of his creation. The monster calls himself "the Adam of your labors", and is referred to as "the creature", "the fiend", "the daemon", and "the wretch" at different points in the book.
The monster doesn't really have a name. Its always referred to as the creature, the monster, the fiend, etc. I think this confusion arises because in pop culture, we think Frankenstein is the name of the monster. In actuality , Frankenstein is the name of the creator: Victor Frankenstein.