Question regarding M37 wool trousers

Hey all! I posted an image of a “hiking” fit in r/VintageFashion, and folks were commenting about the impracticality of it, with one commenter saying that the M37 Trousers were for dress wear, on leave, or office work. I was under the impression that they were part of field uniform, and hence durable enough for something as mild as a hike. Can any of you lovely people on here tell me what’s actually what about them? Thank you in advance!