When people say "there's not a lot of good Life on Mars fic". I've seen this a few times, and it generally enrages me.
Um. Okay. See, I tend to think that's not exactly true.
What there might not be is a whole lot of fic of a certain sort. But that doesn't mean there's not a lot of good LoM fic. It means there isn't a lot that suits your tastes, or hits your kinks, or speaks to your perceptions of what a 'good LoM fic' entails. (Which could be anything? Really? I mean, the show kind of says different things to different people. It says different things to me.)
You know what? There's not necessarily a lot of Life on Mars fiction that mirrors trends in other fandoms. There's not. There are really good reasons for that. Whilst it's infinitely ficcable, it's also infinitely hard to fic.
Just think about it for a moment. Canon of 16 episodes, almost entirely shown from one character's point of view, with reality and unreality converging --- difficult characters to write, because they are really very complex on some levels and caricatures on the other, not to mention Mancunian, in 1973; all meshed together with relatively simple crime plots and existential pondering that gives all kinds of potential negative messages about what life's all about.
Oh, yeah. That's... fun. Do you deal with these implications, or do you ignore them? If you deal with them, which tack do you take? If you ignore them, aren't you taking the easy way out? There's character voice, and plot balancing, and historical detail to contend with.
See, when people say this, I think what they actually mean is, "there isn't a lot of mindblowing, earth-shatteringly brilliant 'Life on Mars' fiction". Which may be true, but is true for all fandoms.
So, if you want to say that in the future? Either put your money where your mouth is and write your own damn fic. Or... accept that there isn't a whole lot of good fan fiction (that suits your tastes, or hits your kinks, or speaks to your perceptions of what a 'good fic' entails) at all.