It turns out that bots have been putting comments in this blog in the hopes of increasing their hitcount indirectly. Due to this spamming, I have introduced 'comment moderation'. If you want to post something, the process is the same. The only difference is that I have to approve anything before it reaches the comments section.
There is another option, where the poster would have to identify some letters on a page, and I wouldn't need to confirm anything. If you prefer that version, I can change it easily.