I can see this point. If I understand it, the Calculus Trap article argues that students should be "learning how to take tools they have and apply them to complex problems."
What I don't get here is that calculus does exactly that: you have to use existing tools (algebra, geometry, arithmetic) and apply them to complex problems ("How many miles did you travel from 2 pm to 6 pm if your velocity could be described according to this formula: <insert quadratic equation>?" "A farmer has 168 meters of fencing and wants to maximize the area of a rectangular corral. What should its dimensions be?"). Etc.
No, those are not complex problems in the way that the article means. If you understand the tools taught in calculus, they are absolutely routine: no thought required, beyond a routine translation of words into symbols. The Calculus Trap is exactly people's unthinking assumption that calculus must be challenging because it comes last at school. It isn't, as taught at school; it's easy and unchallenging, and there are many more useful things for young mathematicians to spend their time on.
[ETA if I sound bitter, this may explain: have I mentioned that DS7 has fallen into the calculus trap somehow - that is, he thinks learning calculus will somehow make him grown up - and is determined that he's doing that next? He'll get challenged, though, I shall see to that, bwahaha...]
