We like comments that promote thoughtful discussion about the article or the subjects they are about. The grandparent comment is not a good comment when judged by this standard. It is not really related to the subject at hand and if it actually did start discussion it would be a hindrance and distraction.
If it had not been the bottom comment already I would have probably downvoted it for these reasons.
If it had not been the bottom comment already I would have probably downvoted it for these reasons.