Why don't I have comments on this blog?
Short answer: People (not you, probably) are jerks.
Do you hate spam? I hate spam. And not only is email spam intensely irritating, but blog-comment-spam is too. If I had comments enabled on this blog, I would have to spend more time moderating them (removing the spam, censoring the angry) than I find worthwhile.
I could outsource this, in part, to some other service, like Disqus or Discourse. However, I'm not fond of Disqus, which is a third-party service that makes money from advertising. Discourse is acceptable, but setting it up is a big project. Then securing it would be a big project. Then keeping it secure would be a big project.
Instead, feel free to email me. There is a link at the bottom of each page which invites you to send email. Real email, not some weird web-form that drops your message into a database so vast it could engulf Sweden without stretching. Go ahead, write to me. If you are a decent human being, or can simulate one in email, I will probably write back.