Messi has been poor for Argentina most of his career, not surprising they may like someone who isn't as flashy but more effective. Obviously with Barcelona he's about the best player in the world, but not so great generally when playing for Argentina.
http://m.goal.com/s/en/news/14552/world-cup-2018/2...
You can't have his record at international level and have been poor. There's social and political reasons he gets bagged in Argentina but it's a myth that he hasn't delivered at international level.