EA did not make the decision to pull Crysis 2 from Steam. The decision was made for them by Valve, which cut Crysis 2 from its digital store due to a new set of business terms imposed upon developers who sell their products on Steam.
"It's unfortunate that Steam has removed Crysis 2 from their service," said an EA spokesperson to GameFront. "This was not an EA decision or the result of any action by EA."
“Steam has imposed a set of business terms for developers hoping to sell content on that service – many of which are not imposed by other online game services. Unfortunately, Crytek has an agreement with another download service which violates the new rules from Steam and resulted in its expulsion of Crysis 2 from Steam.”
It doesn't explain why Steam had no problem with the game being sold on GamersGate, Direct2Drive and other digital services.