I buy all my games from steam..
Except ED because I backed it and you cant
The point is how many sales have been lost by not being on steam. Outside of UK and previous Elite players of yore how many Know Elite and Frontier as a brand and can find the website?
If you compare sales of Elite to COD or GTAV then its not really alot. They need to grow new audiences in other countries.
I saw a report that China Japan and south korea are the growth regions
This weekend COD AW was on free access.
The future First person expansion might capture that segment
Not really a fair comparison. Elite is a niche market game, hence the need to kickstarter it in the first place (OMG i can't believe I just verb'ed that, or that

).
You're better off comparing it to something like Sins of a Solar Empire. Both are niche games, self-published from a mid-size studio.
I do think though that steam would give a lot more visibility to ED. Generally if a game isn't on Steam, or gog, I won't hear about it, and even evil uPlay games manage to distribute through Steam. Many MMOs manage to distribute through steam, so it's not impossible. It's pretty much a closed issue though, as FD have been pretty firm about saying they won't use Steam.
Stardock is another interesting comparison here. They had their own distribution system, before selling it to concentrate on producing their software, instead of a distribution network and promptly put all their games on steam, and I suspect made a tonne of new sales. Ironically, Valve hasn't done that much in software/games since Steam took off. I don't really want to see FD going in that direction, i'd much rather FD use their engineering resources on games, not distribution.