I have read somewhere in discussions that Relic / Sega decided to stop support the game because of low steamcharts, this is a so much stupid reasoning !
Lot of players have bought the game and decided to no playing it just now : for example, some of them were waiting for more content, some others were waiting for more balancing (rangers nerf), because all dow players knows since vdow that the first unpatched version of a dow game is hardly imbalanced !
In my case for example : DOW3 just have came after another game that I love too (Space Hulk Deathwing), so I really started to play DOW3 about around october / november.
Does it means that I didn't liked the game and won't play / support it in the future ? Of course not because I still continue to play it today (in fact I find it really amazing).
So, to summurize, the true question that Relic / Sega should have considered for a dlc / new content opportunity is not how many people are playing the game according to steamcharts ? but how many people would have bought the new dlc ? or how many people would have played the game in a full complete version, in particulary with a Chaos dlc which was really waited by lot of players?
And to ask this question, I would bet my baskets that they would have been Legion...