Physique Modifier VS Skin Modifier

I still wonder why some 3d artist using 3ds max use two different modifiers when rigging characters for production, most artist I have met in my wide association tend to go for the skin modifier rather than the  physique modifier, it confuses me because i learnt 3ds max using physique with the inbuilt tutorials shipped with 3ds max, and now I'm well versed in 3ds max as I have been able to rig characters for my animations and my films, this issue has been bothering for quite a while now, so these questions arose;