I was seconded from Hangar to Line last summer and managed to stay out there for a bit longer, before they missed me too much and dragged me back, screeming with protestations that I wanted to stay outside, even in the freezing cold! I learned more about the systems on the line than in the hangar, because out there you need to get it right first time. In the hangar, if there is a snag, something is done to rectify it, but there is never any feedback that the sang has been cured.
I think that it is recognised that individuals fair in different roles. One guy might be more suited to a hangar environment, whil his mate mught be suited to line work. In the end it is up to the individual to find their own prefferences.