Xbox Live Arcade policy changes = bigger risk.

I was inevitable that once they got a deluge of games the competition would get more fiercer and expensive to compete with. Was a time that you got a ton of concessions, and the small number of games avaliable guaranteed you a big return on your game. For the first year even the worst performing games were getting more than 10% conversion rate.

Now you all but need a publisher to stand much chance of getting your game released.