It's important not to let pragmatism wander into anti-intellectualism.
"pedagogy, psychology, and mathematics" are all well-defined terms with non-bullshit meanings. Montessori, Papert and Bruner are well-known names whose theories would be familiar to anyone with a background in learning theory. McLuhan (the "medium is the message" guy) is similarly well-known in media circles, and if you want to understand why Alan Kay thinks he's important, he wrote about it: https://kokonautlabs.wordpress.com/2013/02/27/alan-kay-on-ma...
I'm not saying you're wrong to dislike the article or Kay, but the way that you got there seems to be by saying "they rely on a bunch of bullshit that nobody understands". How are you, presumably lacking a background in the ideas they are talking about, able to determine the difference between good theory and bullshit?
If you want to reason about something, like how people learn, or how technology shapes thought, how would you do that without building a theory about it? How would you build that theory without ideas? How would you refer to those ideas without names? Is your criticism anything more than just that you don't know the names in a field you aren't familiar with?
God bless the real engineers who make things work; programming and the personal computer were revolutionized with the availability of hardware like TTL ICs, not pseudo-engineers bloviating about "structured programming".
But I've seen the code written by real engineers, and they could perhaps use a little less pragmatism and a little more theory. Thinking in abstractions can certainly lead to bullshit, but I'd rather that than no thinking at all.