I subscribe. It does work. Did you read the linked post of hers? Perhaps your client is throttled or blocked.

Data point 3: does not work for me. Also using NetNewsWire. “Throttled or blocked” changes nothing, if it’s down for half of visitors then it’s down for half of visitors. I highly doubt NetNewsWire is breaching spec or poorly behaved. I bet rachelbythebay is just throttling by IP address and really has a 24 hour limit of exactly 1, so only one person per IP per day can subscribe.