Shouldn't it all be 'alternative education'?

Trips like this are called alternative or outdoor ed. My question is why don't we do it all like this? 

During this week they learned about other cultures, farming, human impacts on the environment, field techniques, biodiversity, classification, team work, problem solving, conquering fear, dealing with conflict, physics and how to cook some healthy tasty food. The photo is a successful egg parachute made for a 12m drop using limited resources in a short space of time.

So why do we usually insist on compartmentalising everything and teaching kids mostly in a classroom? They had an amazing time and got so much more out of this experience then they do from several weeks of science lessons. 

This is the way we should be teaching almost everything. There's forever complaints from pupils that school doesn't seem relevant, from employers that school leavers can't apply their knowledge and from universities that A Level students struggle to think for themselves. So, why on Earth do we continue in the same way and expect things to change?

Get them outside, get them learning through doing and encourage actual independent thought. That should be my role as a teacher, not the exam robot creator I all too often feel I am.