I think it's okay. Just a small quip thrown in from the side that's still relevant to the topic of discussion. It would not be okay (IMO) if you tried to derail the discussion to focus on your link instead; in this case, a regular submission should be made.

To be fair you should just refuse to work on PowerPoint because you will save millions, potentially billions of hours of other people's time that have to endure those presentations.

Crimes against humanity.

Imho, the important thing is the degree to which a comment contributes or adds information to the discussion.

So something like linking an article about PPT overuse in the military w/ a quip is much better than just a quip at PPT's expense. (Given that some people might not be aware of the reported overuse of PowerPoint in the US military)

Ha. I was going to say death by PowerPoint. Or even PowerPoint commandos. I hated working with PowerPoint when I was in the USMC.

Including the article makes it an interesting tangent in my view.