Another good reason to write the CA's or FO's name is for reference when it comes time to interview for bigger and better jobs. It seems just about every interview these days (including some non-airline) is a "tell me about a time when..." format. Obviously, if you pop an engine, you'll remember who it was with but a lot of interview questions are more subtle. So to prepare for an interview, you'll start by going through your logbook to jog your memory and looking for answers that could fit for a possible interview question.

Trust me... I've conducted interviews at XJT and been to a SWA and NJA interview, and VERY recently, a non-flying interview and things are very similar across the board.