It was funny/sad that people commenting on her blog assumed she was male due to the topic.
Or people did not know, and were indifferent to, her gender and used the male pronoun because that is the correct grammatical structure when the gender is unknown. I certainly never pay the slightest bit of attention to the gender of people I read. Does it make any difference?
According to the prestige dialect, yes. Not according to most of the more common dialects of English.