I'm sure a collaborative effort would have resulted in simply removing the 10 unused font variants and leaving the two that are used. That would save 416kb of those 500kb without being tasteless.
This is a good ressource on what designers think of his choices of Arial and Helvetica: http://practicaltypography.com/helvetica-and-arial-alternati.... Quote: "I try to keep the litmus tests to a minimum, but this must be one: you cannot create good typography with Arial."