In small setup yes the developer knowing this will help,but in large companies I would assume this is what solution architect and CTO's do. If we do 80/20 heck even 20/80 with Infra experts and app architect and decide on day one the characteristics and limitations of the software to be developed then you don't need every dev to know the infra and every infra guy to know code. In my experience seeign other super support professional it is that knowledge of how app and tech works make it easy to support. But yeah i training people with this kind of knowledge. I would say 1 in 5 is capable but only 1 in 10 or 20 only make it due to time it requires to know all and able to do ad-hoc work. May people hate ad-hoc challenges everyday . But there some some who take it as day to day.