Well, consider that probably the content was developed by someone who knows what he/she is talking about, and has been later edited by content editors, mistakenly.
The guide to python (and I am currently training up a few folks in python) seems to be a guide for complete retards to learn python. It's woeful.
"retards"? really? that's still a thing that people say?
There are people for whom it hasn't sunk in yet that it's a thing you don't say, and then there are jerks.
Hmmm. I think it has well evolved beyond being a medical term of any kind and is now just an expression for somebody who is being stupid. There is a big difference being somebody who is stupid (something I would never say someone is), and somebody who is being stupid, which most of us do at least once a day.