[nobody314159]

Many jobs require a degree.

Those jobs that only require you to wear a suit don't care what the degree is in.

Now if your future job only depends on your grade - not the subject which would you choose? Studying maths/physics/etc for 4years or doing psychology/media studies/american studies.

[impendia]

I don't know anybody that took nothing other than math classes for four years of undergrad... and I majored in math, and subsequently went to grad school in it.

[hugh3]

I took only maths and physics classes for my final three years of undergrad. In first year, I also took chemistry and computer science.

No, I didn't go to uni in the US.