I'm not surprised at all. Homefront was not that good at all. I had high hopes for the game when they started talking about an alternate reality where the US was invaded and such. But at the end, the game fell short and it was...well, incredibly short! It didn't even bring a single innovative element to the table; the plot is not enough to give this game popularity.
Something like Brink, which I see as a Killzone rip-off, brings some few elements and it's fun to play nonetheless. But Homefront? Well, when you compare it to CoD, which was the point all along, is not that good. Heck, it's not even close to Medal of Honor and, in my own humble opinion, is second best when it comes to FPS.
I always feel bad for the people who worked on the game so hard. Artists, developers, programmers, you name it. It's horrible to work on something for so long, try to turn it into a mind blowing title and then seeing it flop. And then get fired. That's the only reason why these are sad news.