The thesis of that article is that early retirement is simple formula and isn't as complex as people make it out to be. When one of the examples they give to explain that claim is to just get rid of cable and a few lattes it makes me think that they don't actually know what they're talking about.
Firstly, very few people still have cable. Also, I don't know anyone who's spending $1200+ per year on coffee (and, $1200 per year is a lot more than just a "few lattes").
I actually somewhat agree with their formula but I don't like how they put it in a condescending way. It's like claiming that losing weight is as simple as having more calories out than calories in. Functionally that's true but it doesn't really help much.