Peers are humans as well.  Sure, we can try to filter out subjectivity as much as possible, but as long as humans are involved, some remains in the more complex scientific endeavors.  Often we'll see theories evolve simply because the team doing the work believed they were seeing one thing when they weren't.

A keyboard?  Sure.  The machine itself is has aspects of it that are devoid of subjectivity.  But, I thought I alluded to the difference in my first post by bringing up the "machine".  Facial recognition software is a far cry from bit exchanging between an OS and a piece of hardware.