I knew about the insignia being the image of Primus, but was thinking along the lines of who (in the fictional Transformers world, not humanity or real world) designed the logo... and I can't help thinking from a fictional point of view Ironhide had some hand in it because those initials are pretty damn prominent.
I'm sure someone could come up with some pretty witty storylines for how it that I and H just happened to be there.