England are not going to win Euro 2012. Sorry, but it's true. It would take a Greece 2004 effort for England to overcome the likes of Spain, Germany and The Netherlands whilst also not slipping up against the teams England assume they'll beat yet inevitably slip up against.
So, England have relatively little to lose. Getting past the group stage, largely without the help of Wayne Rooney, and entirely without the help of the various injured players England will be missing, would be a good result.
Andy Carroll, along with the likes of Danny Welbeck and Alex Oxlade-Chamberlain, are heading to Poland and Ukraine with a chance to play in a major international tournament without the usual expectations the English public provide because, for once, England fans aren't expecting to win.
It makes more sense to take a risk on Andy Carroll, who may or may not fire, than to pick someone who will probably do a decent job, but will never be a major star.
Andy Carroll is worth the risk considering that the potential pay-off is a striker who could complement, Wayne Rooney for the next few years. If it doesn't work out, it doesn't work out and Roy Hodgson can look to some of the other young strikers waiting in the wings who haven't made the cut this time around.
The worst-case scenario is that England find in Andy Carroll the next Peter Crouch, a player who has done an important job for England down the years.