Professor Krempe represents that little voice in your head that tells you not to do something. If Victor had taken his advice and ended his study of alchemy, the Creature would have never been made and all of this confusion could have been avoided.
Professor Waldman was the professor that piqued Victor’s interest in chemistry. Although he did not believe in all the hype of alchemy, he did not bash Victor for being interested in the study of it.
Professor Waldman can be seen as the first snowball in Victor’s fight. He was like an idea that Victor took and ran with. Professor Waldman cannot