[thisiszilff]

This is partly because the first course in real analysis (and usually the first upper division linear algebra course) is the first proof oriented course most students face. The material isn't necessarily the hardest, but the proof stuff is new to many people.

[pseudo0]

Chongli's experience is much more similar to mine, we covered basic real analysis topics in calculus classes, and the class titled real analysis was a third-year pure math course. It was designed for students who had taken multiple proof oriented classes already and were pursuing a pure math major. It's just one of those things that varies between colleges I guess.