I once shared an airport shuttle with Barry Longyear and his wife, and we fell to talking about blogs. Barry told me that he used to keep a blog, but it got difficult thinking of things to write about, and "so when I had a heart attack, it was a good excuse to drop the blog."
I haven't got a heart attack and I don't intend to stop blogging, but I understand his difficulty. Here is the problem with a blog about writing: It shares a key characteristic with fiction, which is that it's most interesting when things go wrong. Struggles with plot, with editors and publishers, with Internet pirates, with difficult readers, with disastrous teaching experiences -- these things make good fodder for writing blogs. Right now, however, my novel is humming along without much difficulty, my students are all producing, and I am not trying to get any short stories published. I haven't been attending cons (although this will change soon). I sit in front of my computer and write, I walk the dog, I line-edit stories -- and none of that is interesting to read about. There is nothing to watch duller than a writer who is actually writing.
Anthony Trollope, with the dullest of personal lives, was a methodical writer. He set his pocket watch on his desk every morning and produced one page every 15 minutes. If the timing varied, he sped up or slowed down his pen. After a set number of pages, he closed his desk, picked up his watch, and went off to his day job. He did this year in and year out. You wouldn't want to read a blog by Trollope. You need blogs by Georges Sand or Truman Capote, or perhaps a Twitter by Ernest Hemingway ("Shot a lion today.") Even Edith Wharton would be better a writer merely writing.
Barry, I hear you.