I don't give a fuck about the scientific implausibility of Space: 1999. I know it's implausible. But then I also know that telephone boxes can't travel through time, and I love Doctor Who. Go figure. It is in no way a hard science fiction show. The analysis of the show in terms of existential horror is an interesting insight actually.
It's also a fable about a spiritual odyssey. The journey is what's important, not the practicalities of how it would work. I'm a confirmed atheist, but that doesn't mean I don't have a spiritual side, and Space: 1999 speaks to that part of me. God may not exist, but there's a sense that there is some sort of greater cosmic intelligence at work in the universe. The Alphans are being guided on their voyage. Indeed, it's revealed later on that there is a purpose to the whole thing. So that has to make us question whether in fact it was really an accident that propelled the Moon from its orbit, or some sort of divine intervention right from the off. I'm also quite reminded of the work of Olaf Stapledon in a lot of the more far-reaching ideas the series presents.
Space: 1999 is an astonishingly different series from any other sci-fi show before or since, and for that reason alone, I think it's worthy of my attention. It's breath-taking, spell-binding, and awe-inspiring. And that's why I'm a fan.
The second series is mostly shit though.