The bit about kit lenses is complete and utter balls.
The 18-55 that comes with low-end Canons is a good, useful lens that has effective image stabilisation, fast and quiet autofocus, and is sharp. The maximum aperture isn't great, and it suffers from diffraction when stopped down a lot, but still. It works, and it works well. This is exactly true for the equivalent Nikon lens.
A 50mm prime on a crop body is a great solution, but you'll need a 35 or 40, too, because 1.6 * 50 = 80mm, which is too long for candid photography. You'll point the camera at someone, and then have to take two steps backwards.
And a 40mm is more expensive than a 50, and a 35 more expensive yet.
Not only that, but if you shoot the cheapo Canon 50mm wide open (i.e. at f/1.8) you need to know that at short range, the DoF is just a few centimetres. At 5 feet - a not unusual distance for candid photography - it's two point four inches. You've got to focus precisely to achieve good results. It's noticeable when you miss, and not just to pixel-peeping photonerds. What I'm leading up to is that the nifty fifty is a great lens, when you understand what you're doing.
The bit about high ISO is balls, too. Crop sensors produce great images at low ISO, but you need a full frame sensor to reliably go beyond ISO 1600, and realistically you'll want to stay under ISO 800 if you don't want to be managing excessive noise in your images (or turning them into B&W, where noise is grain is art). Some luminance noise is fine, and can add to an image, but colour noise always looks awful.
I don't like the article. It doesn't tell you how to take good photos; it just promulgates the writer's gear predilictions.
You take good photos by seeing things; angles, contrasts, juxtapositions, spaces, whatever. You see something and want to show it to people, so you steal it with your camera. You think about the scene in front of you, and how it makes you feel, and what story you want to tell, and you let that guide how you frame the shot.
You take good photos of people by engaging with them and forming a connection, even if only briefly; alternatively, you see them engaging with each other, and you capture a glimpse into other peoples' lives. An unengaged subject can make a good photo - but solitude is hard to capture without the photo coming off as voyeuristic. There is something to be said for pictures that take us to uncomfortable places and try not to satisfy but rather to challenge us, but that's probably not something people reading an article about "how to take good pictures" are going to want to do.
One piece of technical advice for taking pictures of things that breathe is "get the eyes in focus".
Yet he never mentions this, and prefers to talk about Lightroom presets instead. Which you can buy for just $20!
Notwithstanding the fact that this piece is a giant piece of clickbait designed to sell his presets, this, to me, misses the entire damn point of photography.
Ken Rockwell talks a lot of nonsense, but I'll be damned if he doesn't have a point when he says "it's not your camera". Proof - go onto Flickr and use the Camera Finder to find a nasty P&S camera, and look at the pictures people can take with it.
Example: the Samsung NV7 is an awful camera with hideous ergonomics, aggressive in-camera noise reduction that only makes things worse, and an autofocus system that is frankly on drugs. The white balance is essentially random, and because it only shoots JPEG, you're stuck with it. (There's one in my desk drawer at work. I can't stand to use it.)
But just look at what some people can do with it: