I'm an American that is going to graduate school in Argentina. One thing that I noticed about the university where I'm studying is that there is no "liberal arts" education. If you are in school to study architecture then you study architecture, if you're studying translation then you study translation and as much law as you have to in order to translate legal documents, if you're studying medicine then you study medicine, etc. My girlfriend is from Brazil and she was telling me that it is the same way in Brazil.
Also, it seems like the equivalent to a bachelor's degree takes longer to earn here. For example, getting a bachelor's degree in economics would take 5/5.5 years of study.
I also believe that Bachelor's degrees didn't even exist in a lot of European countries until the Bologna Process was implemented to try and standardize education across Europe.
So I'm wondering, how did the 4 year liberal arts degree where you spend half of your time taking classes in things that have nothing to do with your chosen area of study become the norm in the US?
Your question actually needs to be flipped around: when did other countries stop insisting upon a liberal arts foundation.
The modern university system was born in the Latin (European) Middle Ages, in Paris and Bologna. The medieval curriculum was founded on the liberal arts: the trivium of grammar, rhetoric, logic; and the quadrivium of arithmetic, geometry, astronomy/astrology, and music. Only upon completion of those would a student advance to study the higher faculties: law, theology, or medicine.
For their part, the tradition of founding one's studies in the liberal arts goes back to ancient Greece.
You might be find these answers helpful:
[How did the descriptors Bachelor and Doctor come to signify a person's completed level of education?] (https://www.reddit.com/r/AskHistorians/comments/3n27cn/how_did_the_descriptors_such_as_bachelor_and/cvkf9de)
[Humanist vs. liberal arts education: were they different in the Renaissance?] (https://www.reddit.com/r/AskHistorians/comments/3olhdz/humanistic_vs_liberal_arts_education_were_the_two/cvyc3yk)
I think your question may be predicated on a fallacy; liberal arts majors are not as popular as you think. In this table "liberal arts and sciences, general studies, and humanities" accounts for 46,925 out of 1,791,046(about 2.6%)
https://nces.ed.gov/programs/digest/d13/tables/dt13_322.10.asp