So? He stays pretty busy with Solid / Inrupt and his other advocacy (e.g., the OP article...)
Perhaps he sees the personal blog format as a bit egotistical or otherwise not fit for purpose. Or perhaps he just isn't a naturally talented writer. Its not as if he's shy about sharing his thoughts outside that.
Also worth noting that he and Bruce Schneier, who is a much more prolific writer, share many of the same views and partner together at Inrupt.
Just as an FYI, whether lie detector tests are accurate or not, lying in a polygraph interview for a federal background check is a crime. Polygraph interviews can and do sometimes lead to criminal prosecution.
Of course you can. "Free kittens, call 202.555.1212"