Well, some people felt let down and that's their choice. My only away game (against Atletico during the volcano week when most of the support had to travel with train or car to Spain) I remember Carragher and a couple of others applauding during warm down. That was a nice gesture but at the end of the day it's the commitment on the pitch that matters.
Still think it's a nice gesture from Brendan to type that letter. He's an honest guy it seems and it seems he really feels for the fans and the club which is a great thing.
The only silly thing here is that this (non-)issue puts some fans in different camps. We, as fans, need to stand by the club and show our support, not resort to petty argument.