Are you really learning the skill, or are you sampling it? One semester is maybe 40 hours of instruction. Even twice that in practice puts you at 120 hours. I hardly think that is enough time to become a good skier, etc.
40 hours of skiing is 10 4-hour sessions. For a young adult in decent physical shape and with good instruction, that's enough time to establish a base of technique and confidence.
That's pretty much all you get in most undergrad courses anyway. It's usually an intro to, or first taste of, a sophisticated subject that would take a long time to master. It's only after many such intros (i.e. many hundreds of hours of study) that the student will begin to develop a more sophisticated understading of their chosen field.
In that light, is a 1-credit skiing course any different from a 1-credit astronomy course?
People are different. I knew a couple newbie ballroom dancers who picked it up incredibly fast. But they were one in a few hundred. Ballroom dancing looks natural, but it isn't. Every move works against natural body movement. It takes a while.
For example, when walking, one sets the foot down heel first. With ballroom dancing, it's ball first.
