Edward Tufte's - see earlier post - criticism of David Galenson's book included Galenson's use of the word "I" (or rather too much use of the word "I"). I think that the main reason for this has been the move away from using the passive to the active voice:
"The hypothesis tested is ..." versus "I test the following hypothesis".
On a similar note, I also see articles where, instead of "I", the author uses, "We". This works fine when there are multiple authors but I also sometimes come across these even though it is a single-authored paper. I find it a little disconcerting but am willing to let it go.
Personally, I've always preferred the passive voice but at work, we are constantly being urged to write using the active voice. I'm not sure why there is a trend toward the active voice - I feel like I'm writing my resume or something.