bollocks. we had / have Doctor Who, Blakes 7, Star Trek, Ultraviolet, Flash Gordon, Thunderbirds, Space 1999, Star Cops, Red Dwarf, Stargate, Hitch Hikers Guide to the Galaxy, Lost, Battlestar Galactica, Space above and Beyond, Sapphire and Steel, Babylon 5, ....

 

I can can go on. a lot. there are many fine SF shows other than firefly.