Nick playing the "no one cared about how I felt" card only was an excuse to get all the money. Didn't he make out with Donna? Unless he thinks that was his doing all alone, and Donna was just "there." The fact that no one cared to be in an alliance with him or partner with him has also to do with how he communicated with others, but it was a good stategy to lay low and not burn bridges, but like Rachel said: "money is ugly." Nick played ugly, but it seems like this is the goal for such kinds of games. Nick just used that as an excuse to play ugly.