The real drawback isn't the team leaving, its groupthink. I think we've all experienced this firsthand at some point in our lives, especially when we're getting hired for the first time - you walk into a room with the entire programming team. You are a stranger, but the team know each other. The team has agreed upon a common methodology, a common programming language, a common framework, maybe they all use vim on the Mac. You walk in & say something stupid like, Hey guys, lets just do this in xyz language, you open your windows laptop & fire up TextPad & next thing you know, you're getting those weird "hey he's not really a part of our team" look. Then you pretend like you hit the wrong button and quickly bring up cygwin & they heave a sigh of relief :)