I would guess that both of you received downvotes because both comments failed to provide any explanation for the view expressed. I think it's good practice on HN to briefly introduce a technology where it's safe to assume that a majority are not very likely to be familiar with it, so that the comment becomes meaningful on its own.
If you had stated: "You are comparing apples to oranges here because Dragonfly only exists on BSD, not on Linux, and as such may not be a viable choice for most users." I think you would have received no or substantially fewer downvotes. If you then had in addition to that provided a quick explanation (or more) of what "Dragonfly" is, you would have gotten upvotes instead, because that would have taught a number of us something we did not know yet.
If you had stated: "You are comparing apples to oranges here because Dragonfly only exists on BSD, not on Linux, and as such may not be a viable choice for most users." I think you would have received no or substantially fewer downvotes. If you then had in addition to that provided a quick explanation (or more) of what "Dragonfly" is, you would have gotten upvotes instead, because that would have taught a number of us something we did not know yet.