I'd never heard this before but I can see why naming the subject helps over using "I" or "we." Writing "Jason likes cake" on my website would tie me to the "cake" keyword moreso than "I like cake", right?
I took it to indicate a bias against personal blogs, fiction, and other forms more likely to be in first person. That's in contrast to sources like Wikipedia, or virtually all news, which are in third person. Where it gets weird would be informally written blogs that are still using the first and second person.... or interviews perhaps?
