I agree with you. Star Trek TOS only had two good seasons. Season 3 was widely panned. And it still spawned a massive franchise.

Plus there have been dozens of one-series sci-fi shows (Almost Human, Terra Nova, Space:Above and Beyond, etc.) and none have the same pull as Firefly.

Interesting that all those you specifically named aired on Fox, which is where Firefly aired.

Other science fiction shows Fox killed after not more than one season were The Lone Gunman, Harsh Realm, Minority Report, Second Chance, and John Doe.

Others did make it past the first season but not past the second, such as Dark Angel and Terminator: The Sarah Connor Chronicles.

Even shows that make it longer often have trouble on Fox. Futurama for example was put in terrible time slots that often got preempted by sports which made it hard to grow its audience, and most of the time the creators had no idea if the current season was going to be their last. They had to keep trying to write season finales that would also be good series finales if they got cancelled between seasons.

They also do this to shows in other genres. Lucifer for example got cancelled after 3 seasons, with season 3 having ended on the biggest possible cliffhanger there could be for that show. That was very annoying.

My rule has now been for a long time that I will not watch any new scripted series on Fox that has any kind of ongoing story. If there are enough good reviews and word of mouth to make me want to watch it I'll wait until complete seasons are available on streaming, and then only if there exists some N such that if I watch to episode N and stop there won't be any cliffhangers or important ongoing story arcs open.