Aren't you doing a bit of an injustice to that article by cherry-picking that line? It's obviously written humorously; the very next words are:
> Personally, I have always found it important to actually understand the things I am using. I remember learning about Cross Products and Quaternions and being confused about why they worked this way, but nobody talked about it. Later on I learned about Geometric Algebra and suddenly I could see that the questions I had were legitimate, and everything became so much clearer.
Clearly, "who cares as long as" is not the true belief of the author, but rather a mocking call-out of teachers who do think that way.