Granted, the userbase for the two other consoles is significantly larger. However, we think that EA's poor sales on PS3 can be accounted on more than just a small userbase. We're pretty confident that the company garnered quite a negative image when it produced sub-par ports of their most popular games on the system. Madden 08's fps debacle certainly hurt them amongst Sony fans. Their upcoming port of The Orange Box may not earn them much more slack either (we'll have a hands-on report from a final version of The Orange Box soon).
Once PS3-centric development truly begins at EA, such as with the upcoming Burnout Paradise, we're certain that the moneybags will look greener under the PS3 tree.