The problem is that there are just so many different space sci-fi universes out there, you’re bound to miss some, and every last one of them is ridiculously beloved by SOMEBODY.
For example, I was bummed out that they don’t include any Wing Commander ships, or anything from the Descent or Freespace games. Not exactly as big as Star Wars, sure, but these are still well known classics of the genre. (That and I personally will always love the Athena Fighter-Bomber.)
Edit - Well I’ll be darned! The artist updated the image since last I saw it! Freespace and Wing Commander added! Woot!